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MG Midget and Sprite Technical Wolseley 8' brakes BBS discussion at MG-Cars.net
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MG Midget and Sprite Technical - Wolseley 8' brakes
| I have obtained a Wolseley 8" rear brake set up for the midget, new drums, brake shoes,adjusters, wheel cylinders,springs and back plates, has any one done this conversion and if so would they tell me please how the adjusters fit ? even better would be a picture if possible and any other comments would be welcomed. Thanks in advance |
| Rob Newt |
| Interesting ... Im looking forward to following this thread |
| Prop |
| ROb, Sounds great im looking for a set myself, i think that is the sebring set up if so try here for a picture , only shows front but might help http://www.spritespot.com/gallery/sprinzelsebringsprite/BRAKE_2 |
| Andy Chaffey |
| The adjuster sits within the slides on the top of the wheel cylinder Remember the wheel cylinder will sit towards the back of the car in a vertical position and not on top in a horizontal position. |
| PeterJMoore |
| The photo of the Sebring set up appears to to show the Riley / Girling brakes. Are there books with this stuff in? |
| Daniel Thirteen-Twelve |
| Daniel yes I have the lockheed cylinders as I do believe I have a book that tells me the Girling are no longer available, but no picture ! Peter does this mean you have fitted this conversion ? I had seen that the cylinder fits in a vertical position as the hand brake linkage needs to be twisted(I have the adjustable type so should be o.k.) Still not sure from your discription how the adjusters fit, I have posted a picture to make sure we are talking about the same thing.  |
| Rob Newt |
| Rob, can you point me in the right direction for the parts ? thanks Andy |
| Andy Chaffey |
| Seeing those 'snail cam' adjusters reminded me of my ~1956 Minor. See item 60 from the Moss website for Morris Minor: http://www.moss-europe.co.uk/Shop/ViewProducts.aspx?PlateIndexID=17088 HTH |
| Doug Plumb |
| you see the black triangular piece on the cylinder it is the highest point on the cylinder when fitted You will need to remove the bleed nipple, the black triangle, punch out the retaining pin to release the handbrane lever to fit it to the backplate, and you may have to tap the cylinder quite hard to get it in to position the adjuster then sits on the top of the black triangular piece, with the flat of the adjuster against the black metal. the upper shoe then sits into the centre of the pall on the adjuster. Remember to keep it at its lowest point for refitting the drum and keep the screw facing outwards. Hope that helps |
| PeterJMoore |
| Peter your a star, Ive got it now how it goes, I will put it to the test the weekend and post some pics to see if it looks correct, the funnything is after my last post I was having a look to see how the cylinder fitted into the back plate... you have now answered my next question as I didnt realise the pin in the cylinder was meant to come out so i could remove the arm ( I thought this bu@@er is never going to fit) Doug the shoes and drums I bought were from the Morris minor centre Birminham, same as the Morris Minor fronts I do believe but different back plates. Andy Here is your contact address http://www.wolseleyworld.com/1500 Speak to Andy, nice bloke who doesnt mind selling to non Wolseley folk. |
| Rob Newt |
| Ill give you a couple of hours of swearing before telling you how to bleed them :P Fire me an email Rob |
| PeterJMoore |
| >>>>>>>>Daniel Thirteen-Twelve, United Kingdom, daniel1312@aol.com The photo of the Sebring set up appears to to show the Riley / Girling brakes. Are there books with this stuff in?<<<<<< Hey danial, I did some checking... the only book I could find with this type of stuff featured in it, was this one... Prop  |
| Prop |
| I broke a Riley One point Five and a Wolsley 1500 not long before I came out to Aus. I sold the Wolsley brakes straight away and have kept the Riley ones. It was a popular conversion in period and as the book Prop mentions (great read by the way) all the info you need is in there....! Thanks for the heads up Prop... :-) Mark. |
| M T Boldry |
| I have thought a few times about doing this 8" Riley brake conversion, but I then start to wonder how effective they are, against the later 7" twin cylinder set up, thats my main question ? Keeping in mind that the eight inch are also a single leading shoe, and in period they replaced a 7" similar set up on Frogeyes. I have larger discs up front so I wanted to improve the F to R balance. The later Spridget set up I find to be very good, when set up properly (eliminating slack in the across hand brake axle bars was the best thing I have done to my own) I have fitted 1.5 inch wide mini front shoes to my own cars which also helps a little, and my handbrake will lock the rear wheels at 30 mph without problem. Ian |
| Ian Webb '73 GAN5 |
| Ian The reason for changing the rears to 8" was after changing my front calipers to 4 pot Kad I found the balance between the front and rear to be all wrong(loads at the front and nothing at the rear) this was confirmed when it whent for it mot on the brake tester roller. I had renewed my standard drums, shoes and cylinders and was still not happy so hopefully this 8" conversion will do the trick,I must say the wheel cylinder on the Wolseley looks like it is built for the job with the handbrake arm going directly into the cylinder,the only thing I now might have to do is fit a Mini bias valve so I can the balance to my liking,I will post my thoughts when its all finished. |
| Rob Newt |
| Rob If you need one of those mini bias valves I have an NOS one, its proffesionally modified to be adjustable, would be happy to sell it reasonably. The Riley 8" Lockheed set up is the same as a Frog 7" setup which I do not find that good, so I was only pondering how good the 8" was. Ian |
| Ian Webb '73 GAN5 |
| Ian Could you email me a pic of said bias valve please? |
| PeterJMoore |
| Re Peter's request for a photo - Ian, please dont be shy by posting it here for others to enjoy as well!! |
| Doug Plumb |
| Hi Rob, you must have the wrong book because I can see a photo and a line drawing on page 128. I'm 5 mins from J3 of the M6 if you want to see the brakes fitted in the metal. Don't forget to re-flare the brake pipes. I've never had any trouble bleeding the Wolseley 8" drum set up. The 8" drums obviously have a larger swept area than any 7" drums and being larger are much more resistant to fade. The handbrake is also extremely effective and a far better design that doesn't rust up. What it lacks is an aluminium alloy minifin drum though assuming there was a large enough order it would be possible to have a pattern made and some cast. On a brake dyno look for 200Kg per wheel at the rear and the same for the handbrake on 8" drums and with well bedded in shoes maybe 230Kg - 260Kg max on the handbrake. I've not seen more than 170Kg on standard 7" drums Obviously you'll need more at the front tha the back - maybe 230Kg per wheel. I'm always interested for anyone to share their MOT brake dyno figures either on the BBS or by e-mail. I haven't done a lot of work on checking brake bias using known front and rear brake dyno figures in comparasion to the car weight and set my car up in the dry. I suppose the heavier the car the greater the weight transfer under braking and the less rear brake you can run. |
| Daniel Thirteen-Twelve |
| I will try to find the valve tommorrow and post a photo. Daniel, good point about brake dyno figures, I will try to remember and make a note of them at the next MOT, perhaps others will also, it would be interesting to make comparisons. Ian |
| Ian Webb '73 GAN5 |
| Thanks Ian ;) |
| PeterJMoore |
| Like this? http://www.spritespot.com/gallery/toomanyspridgets/len1 |
| rob thomas |
| Daniel my apologies, I think I need to spend more time reading said book and stop posting questions I all ready have the answers to. I must try and dig out my brake dyno figures, as I am friendly with the mot tester a before and after test would be a good comparison. no one so far has said how they find them now fitted to their own cars ?? Thanks for picture Rob |
| Rob Newt |
| Pete/Rob Here is the modified Mini pressure limiting valve. In the box with it I found the original bill form Aldon Automotive, dated Aug 1988 for £31 ! Its never been fitted, I was in the process of gathering parts to fit a 9" big brake kit to the front. I never did get to fit that either ...... a new job kept me very busy for the next 15 years and it all got put into safe storage. I will be selling that kit soon, as I am trying to get a pot of money together to build an new engine. Ian  |
| Ian Webb '73 GAN5 |
And another
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| Ian Webb '73 GAN5 |
| Sweet Thanks Ian, for some reason i had it in my head that it was a standard 4-way with built in adjuster. Hence the intrigue. There are modern equivalents available of what you have, and at the same price as what you paid way back, but they dont have the "period" look about them. Does the knob click, or just turn? |
| PeterJMoore |
| Hi Neil The more usual set-up for 8" rear brakes is to use those from the Riley 1.5 - you might think the Wolseley would be the same but in fact it had Lockheed brakes and the Riley had Girling. I have a Riley set-up on my Sebring Sprite. I actually bought Wolseley ones first and found difficulty in lining up the levers for the handbrake, etc but no doubt it could be achieved somehow. If you are interested in learning more about the Riley set-up give me a shout. All the bits are available (I think) and the drums can be bought new as they are Morris 1000 fronts. By the way when fitting the Riley brakes to a Sprite you change the wheel cylinders to ones of a smaller bore 5/8" instead of 3/4". All the parts are shown on my website including a photo: www.sebringsprite.com/GirlingBrakes.htm Good luck. Martin |
| Neil K |
| The bias valve is what I've used on my car for many years. What it does is restrict how much pressure goes to the rear brakes. I think you wind it in to get more rear brake and wind it out for less. There is no click or position sets on it. It will bolt on the axle replacing the strong brass 3 way union. The Handbrake rods need a twist applied to them when used with the Wolseley 8" drums. The late Morris Minor front drums also fit the Wolseley 8" brakes. The more usual 8" conversion may have been the Riley in the in the 1960s, though I'm not certain that was every the case but am certain that for about the last 20 years it has been more usual or usual to fit the Wolseley brakes, due to the NLA of the Riley brake cylinders. Probably Wolseley's were also made in greater numbers than the Riley so rear drums sets were always more plentiful for aftermarket conversions. For anyone building some sort of Sebring replica it would probably be period correct to use the Riley brakes while for anyone building a 'common or garden' period correct Spridget then the Wolseley are fine. |
| Daniel Thirteen-Twelve |
| Ian do you want to send me an email regarding price for bias ? rob at cornishconnectionpasty dot co dot uk. Pete <<you see the black triangular piece on the cylinder it is the highest point on the cylinder when fitted>> I think this is why you might have difficulty bleading your brakes, I have done a test fit today and I am pretty sure the black triangular piece goes at the bottom, therefore the bleed nipple is then at the top so air rises and simple to bleed, so my thinking is have you put your back plates on the wrong side ? Any thoughts ? |
| Rob Newt |
| Pete As Daniel says it doesnt click, but somwhere I have seen the same one with a tab screwed to the side to make into a click type of job. I always planned to connect it inlne, to F-Rear brake pipe that was inside the cockpit on that car, on the floor beside the tunnel drivers side. As you say these days there are plenty of modern ones availble. This was on a car that was mainly road rallied in the 80's. Rob, I will email you soon. Ian |
| Ian Webb '73 GAN5 |
| <<The photo of the Sebring set up appears to to show the Riley / Girling brakes. Are there books with this stuff in?>> Yes, and not just your own, Daniel! <<<<<<<<<<<<<<<<<<<<<<<<<<<<<< (see left, send me an email - One or two copies still available - since product placement is all the rage!) That is, if people want to know all the Girling part numbers used on the Sebring Sprites. Bear in mind - it was an authentic homologated version of the Sprite, not just some backstreet bitsa [;-)]. It's not the Riley wheel cylinders that are NLA, it's the smaller ones the Sebrings used that are impossible to get hold of - the Riley ones are around, though dearer I'm sure than Wolseley ones. The Wolseley outsold the Riley by something like 7 or 8 to 1 (from memory), so it's not surprising there are many more s/h Wolseley bits around now. New, I wouldn't think there'd be much if any difference in parts prices, so I don't think it likely that any of the Sebring Sprites used non-Girling parts. For US BBsers - the Nash/Austin Metropolitan used 8" Girling brakes, and I think the rears will be readily available from Met suppliers. In the UK, the Marina also used 8" rear drums (though the drum has the hole filled in) and they fit a Sprite axle. All the BMC B-series Farinas also used 8" rear brakes, I think, which would also be Girlings ... Other products may be available!! Tom |
| Tom Coulthard |
| Daniel - the bias adjuster is a single input, single output, therefore not suitable to sit on the rear axle without an adapter to fit it to the current t-piece, but inline and preferably somewhere it isnt going to get covered in road dirt. It is a flow restriction as opposed to pressure based, wind it clockwise to remove rear brake bias and counter clockwise to allow full flow to the rear, the same as 99% of hydraulic flow control components. Rob - something to do with the backplate fitment prevents it from sitting the other way round, you will see what i mean when bolting them up. Tom - awesome information, thank you. |
| PeterJMoore |
| Hi Peter, The bias adaptor certainly looks like a single input DUAL output because it looks like mine (photo attached) only with a different type of adjuster. Yes, flow restricted, rather than pressure restricted - achieves much the same thing but in a different way If someone posts a clear picture of which way up their 8" backplate is I'll check mine. I also have a spare set I can look at.  |
| Daniel Thirteen-Twelve |
| Ahhhhhhhhh I see the input now on the underside ;) Sorry, had not noticed that on the previous photos. |
| PeterJMoore |
| I think Daniel means as per the photo below. I would guess the T shaped adjuster has a point on the end which restricts the fluid flow to both the rear brakes as it is screwed in. This then reduces braking to the rear and in turn increases braking to the front.  |
| Doug Plumb |
| Ok, conversion all finished today, brakes all bled 1st time with no problems, brake and hand brake performance all show a slight improvement so once I have bedded in the shoes it looks like a well worth improvement, hopefuly may the brake dino will confirm this. one thing i would like to clear up is the position of the cylinder, I have fitted the opposite to what Pete suggested and I am pretty sure they are now correct, please see attached picture so someone can confirm this.  |
| Rob Newt |
| Shouldnt the bottom shoe be reversed so the leading end is opposite the adjuster? ie at the 7 oclock position. My earlier link to the Moss website seems to indicate the equivalent of that. I am of course open to correction. |
| Doug Plumb |
| I have to say I've got a lot more interested in my own installation after reading this thread. Yes, I do have the bleed nipple uppermost as Rob has done with his installation although I've taken a photograph of the opposite side of the car (mine is of the drivers (rh) side of the car in a rhd car). Photo won't load - file size at 1.79Mb is too large! The Lockheed drawing I have includes an information box which states' Leading and trailing characteristics in both directions of wheel rotation'. That drawing also shoes one shoe which clearly has a trailing edge and one shoe which doesn't. I don't have the shoes on my car (at least on the side I checked) the same as Rob has because on my car the lower show does have the leading edge correct but the top one isn't. I'll investigate further with my spare set. If anyone wants a photo I'll e-mail it. |
| Daniel Thirteen-Twelve |
| The Wolseley 8" rear brake is a single leading edge design sometimes known as a leading and trailing edge design. The shoe that fits onto the Micram adjuster can only be correctly fitted in one position. This shoe is the trailing shoe on my car and Rob's. The other shoe has to be the leading shoe but can be fitted in one of two positions. The question is whether the leading shoe should have the end of the shoe where the material fits almost flush to the end of the shoe as the leading edge of that shoe or not. In one reference book I have on brakes I found a drawing that shows the friction material is actually longer on one shoe than the other when in reality all the shoes I've ever seen has the same amount of lining on each shoe. |
| Daniel Thirteen-Twelve |
| Daniel, Had my MOT yesterday - rears 150kg (standard 7"), handbrake 30% efficiency, guy said was better than most modern cars - noted some moderns only just pass. Fronts were 80% efficiency - standard discs, green stuff pads and servo (if that helps ?) Somewhat Pi**ed off with my headlights (Wipacs), rubbish quality had corroded a reflector after only 2-3 years and very little use - fitted a new set of Cibie 180's for MOT - hope they are last longer(can no longer get their superb Biode lights that I used to use). R. |
| richard boobier |
| Spoke to Andy today from Wolseley services and Pete is right and I am wrong, the cylinders on a Wolseley 1500 definatley sits with the adjuster on the top. So that leaves the problem with the leading edges. So my next step to try, is to modify the bottom shoe to fit into the adjuster, therefore then having the correct leading edges on both shoes. I dont realy want to remove the plates and cylinders as everything line up very nicely with the handbrake. |
| Rob Newt |
| There are no leading edges only one leading edge because the design is single leading edge. If the Wolseley design did not see fit to modify the shoe or provide anything other than identical shoes there what can be gained by modifying how the shoe fits, bearing in mind that with a single leading edge design only one shoe can be leading. The backplates are handed left and right. The backplates can be bolted to the axle in one of 4 different positions: two positions with the slave below the centre line of the axle and two positions with the slave above the centre line of the axle. The choice then is to have the micram and triangle section uppermost or lowermost but always above the centre line of the axle. However, whatever position it is in does not change that only one brake shoe can lead and the shoe that fits the Micram only fits correctly in one position. |
| Daniel Thirteen-Twelve |
| Thanks Rob, I was actually beginning to doubt myself there. You can now have a go at bleeding them the fun way :P |
| PeterJMoore |
| I have fitted the RH backplate on the LH side of the car and vice versa. I see that unless I'm mistaken Rob Thomas has done exactly the same. We also both have the adjuster at the bottom and the bleed screws at the top. |
| Daniel Thirteen-Twelve |
Bit late to be breaking news, but this is the exploded diagram from the BMC Workshop Manual for the Wolseley 1500:
 |
| Tom Coulthard |
And a pic:
 |
| Tom Coulthard |
| Cheers Tom Thats how I have now fitted one side as Mr Wolseley confirmed, so no need to modify shoes, just change back plates and flip the slave cylinder, job done. |
| Rob Newt |
| Putting the wheel cylinder in the lower rear quarter is the only orientation which gives the brake rods a horizontal line to the compensator, which of course is bracketed below the axle. (To be fair to Daniel, that's what he says in his book, unlike his posting above.) With regard to the shoes, there is some confusion here as to the leading edge of the linings and the leading and trailing shoe. A leading shoe is one that pivots at its rear end, relative to the direction of wheel travel - this means that its front end 'digs in' when applied, producing the useful 'self-servo' effect. A trailing shoe pivots at its 'front' and then just ... trails. Rear brakes are usually leading-and-trailing to provide decent braking in reverse, when the trailing shoe becomes the leading one. The positioning of the lining on the shoe is another matter entirely - and not always what you might expect intuitively. On Ian's point about the later Spridget 7" drums - sadly, they're not 'twin cylinder' (which 2LS systems are). They have one cylinder with two pistons, which just means that the slave cylinder doesn't have to slide - they don't provide any more braking power. Oddly enough, though (and contrary to what Daniel implies), the greater lining area of the larger drums doesn't necessarily provide more stopping power either. What it does is lower the pedal pressure for any given retardation rate. That is counter-intuitive to the point of spooky. Tom |
| Tom Coulthard |
| Hi Tom, It's never too late for breaking news and you've saved me the job of scanning my exploded diagram from the BMC Workshop Manual for the Wolseley 1500. I admit it didn't know the source of it, to me it's just the 'other diagram I have'. The diagram shows the slave on the lower portion of the back plate almost dead centre. However, the drawing isn't clear on the orientation of the 4 axle mounting holes on the back plate which are NOT in a centre line from the centre of the slave to the centre of the pivot point for the non-slave end of the shoes. What seems, or seems to me, to be the case from what you and Peter say is that you both agree the slave is fitted to the backplate below the axle line and to the rear of the car. YES / NO ? So what I should have said above is: The choice then is to have the micram and triangle section uppermost or lowermost but always TO THE REAR OF THE CAR. However, whatever position it is in does not change that only one brake shoe can lead and the shoe that fits the Micram only fits correctly in one position. I don't agree with your statement, Tom, where you say: Putting the wheel cylinder in the lower rear quarter is the only orientation which gives the brake rods a horizontal line to the compensator, which of course is bracketed below the axle. (To be fair to Daniel, that's what he says in his book, unlike his posting above.) I disagree because looking at my car with the RH backplate on the LH side of the car and the slave above the axle line but to the rear the handbrake rod is horizontal or very near horizontal (just been down to a cold garage to check with the car on the wheels). Is that the way I've always had the slaves on my car? I think almost certainly yes. I also think the way I've fitted the backplates and slaves is the way I'll continue to recommend, as while it may not be the way Wolseley did the job, it does put the slave bleed screw uppermost which I think makes sense. So a summary at this point might be that two positions of slave will produce a horizontal handbrake rod and these two positions are both with the slave to the rear of the car YES / NO. I think that the larger lining area of the 8" drums must provide more stopping power otherwise how is the extra torque reading on the brake dyno accounted for with 8" drums compared to 7" drums (between 30-60Kg per wheel) Hi Peter, the slave cylinder is never vertical and it's never horizontal - at least not on any of the 3 sets of Wolseley back plates I have, 2 sets of which came on axles. It will either be at 36 degrees below or 328 degrees above (clearly there is a margin of error in my measurements of 4 degrees). Hi Rob, I'm nonplussed that you'll thank Tom for his information that means you won't need to modify the brake shoes. Whether or not you agree with my comments about orientation and fitting of the 8" drums I had already said there was no need to modify the shoes. Anyone/everyone else and just to make clear. I've not set myself up as an expert who can never be wrong. Rather I'm always interested in doing things the best way correct, even it means at first I've done things incorrectly and have to eat humble pie. I've found this thread extremely interesting (I promise to get out more starting with Oulton Park this Saturday) and while I'm not planning to change how I've fitted the brakes on the car I do plan to write more clearly about this conversion in future and take more photos. I'm also grateful especialy for everyone's comments so far and anymore still to come Finally, I do have a spare axle, handbrake rods, Wolseley handbrake cables, both Sprite/Midget and Wolseley compensators and brake parts so might do some mockups out of interest and photos. Feel free to drop by and watch if you bring some biscuits! |
| Daniel Thirteen-Twelve |
| The mounting flange for the brake backplate is at a different orientation on the Wolseley 1500 back axle (at least the two I have) compared to my spare Sprite/Midget axle. I haven't measured the difference in degrees. |
| Daniel Thirteen-Twelve |
| Daniel, Tom's comments regarding pad / shoe surface area are correct, in that a larger brake pad / shoe area doesn't give more braking force and hence braking torque, friction (specifically Newtonian friction in this instance) cares only about the normal (perpendicular) force at the shoe / drum interfaceface times the coefficient of friction(mu). So everything else being equal such as mechanical ratios / hydraulic ratios in the actuation system and mu being the same for both shoes types then the braking force will be the same. The braking torque however is braking force times radius and the 8 inch drum has a larger radius.... Cheers Spencer |
| S Deakin |
| But if you are talking braking power, the larger surface area will disapate heat more rapidly. And that is important in braking force applied for another reason: As the temperature increase, the coefficient of friction decreases. So that larger drums will retain greater braking effort under hard use. But more importantly, the handbrake will work better for the reason Spencer outlined :-) |
| Paul Walbran |
| Hi Paul, I was talking more in the context of an MOT test brake torque / brake dyno as I assume Daniel was quoting the differences in torque in these types of tests which don't really bring heat dissipation concerns into play - so can only be due to effective radius asssuming all else is the same. Yes Mu does vary with temperature but definately not always as simply as you mention, i.e. "as temp increases Mu decreases", I don't have any electronic copies with me, just hard copies and no scanner but all of the Pad materials (mainly Carbon Metallic Motorsport pads - Performance Friction) I have data for require reasonbly high temps to get to thier peak Mu and remain constantish for a 100 - 150 degs range before they start to go the otherway and Mu drops. The organic pad data I have seen (again Motorsport type pads) has the same characteristic albeit at lower peak temps. But I don't know the temp / Mu specifics of the shoes under discussion. But yes generally if fade and / or wear is a problem a larger pad / shoe area will help maintain braking torque levels. I was just trying to make clear that increasing the surface area of brake friction material doesn't = more braking force / torque due to the presence of more material which many find counter intuitive. Hence larger shoe / pad area would only help if you had a system which was operating beyond the Mu / temp limit of the friction material. I don't have specific rear brake shoe experience (mainly rear discs on other types of vehicles) but with the low level of brake contribution from the rear axle of a Midget (or any car for that matter) does the rear brake shoe performance deteriorate noticably in a Race / hard road use environment? (not hand brake use - just normal braking) due to heat effects at a greater rate than the fronts deteriorate hence a genuine loss of retardation performance? In my experience of discs all round the front performance is always lost first requiring more bias to the rear as a race progresses to maintain balance. Cheers Spencer |
| S Deakin |
| Too late to edit the post... So most decent quality friction material has a band / range of temperature operation in which the Mu remains pretty near constant despite the change of temp but obviously then drops beyond this range |
| S Deakin |
Just found this off t'internet for Pagid pads - I have no experience of them but still serves to show how the Mu varies with temp |
| S Deakin |
| Hi Spencer Agree completely that performance against temp is not linear and with your more detailed analysis. On the track rear drum brakes hold out reasonably well, but rallying on some of our great gravel roads here it is another story as you need much more bias to the rear - not only for the reduced weight transfer on the less grippy surface, but also a net rear bias to set the car up sideways when cornering :-) Add to that the extra weight on the rear from codriver, spare wheel and enmergency tool kit and the rear brakes can be working as hard as the front. In my MGB I once completely knackered a set of shoes in one rally stage thanks to a combination of red mist and several fast straights (110mph on gravel in a B is quite exciting) linked by very slow 90 deg corners. Less than a stage come to think of it, the linings disappeared completely about a mile from the finish, along with the contents of the wheel cylinder. Fortunately I had warning the corner before that something was amiss with the brakes so the "pop" and pedal to the floor wasn't unexpected. We got to the end of the stage with lots of dramatic brake fluid smoke from the left rear. |
| Paul Walbran |
| Hi Paul, Thanks for sharing your experience, yes low Mu conditions such as wet race tracks and gravel rally stages demand a more rearward brake bias due to the reduced longitudinal accelerations achievable in order to use the brake bias to help reduce the understeer balance. Phillip Island / Calder Park and Symmons Plain is as close as I have got to your shores (back in the day)but still just on the black stuff ;) Still interesting to know it is possible to 'fry' the rear shoes of a similar layout vehicle in the 'wrong' conditions... Cheers Spencer |
| S Deakin |
| several of the front-runners in FISC used to suffer lack of rear brakes at inopportune moments, and I've personally seen one of them in a gravel trap with the brakes on fire - twice! |
| David Smith |
| Hi Spencer thanks for explaining why the 8" brakes work. Everyone else - I've spent some time assembling my spare Wolseley 8" brake unit to my spare Sprite/Midget axle so I can get a really good photograph of how I recommend it's fitted and why. It's taken me longer than I planned as I had hunt around for parts like the handbrake compensator and bracket etc and so it's not finished. However, I have managed to grovel under my car with the kid's digital camera and take a snap to show the alignment of the handbrake rod (B&G adjustable type) in relation to the axle casing etc. I've even worked out how to save the image smaller so I can post it here. Interestingly, probably with the Wolseley LH plate on the LH side of the Sprite/Midget the lever for the handbrake rod will be in an identical position to my installation only the other way up [I'll check this on my spare axle in due course]. But, it would require the brake pipe to run below the axle and make the slave bleed screw the lowest point in the installation. Anyone else care to post photos?  |
| Daniel Thirteen-Twelve |
| Hi Daniel Thats just how I fitted mine at first attempt,(see previous picture) cylinder at 2.00 oclock and bleed nipple at the top but according to Mr Wolseley brake shoes could not be fitted correctly with the cylinder this way. So by the weekend I shall have the plates changed over to enable me to fit slave cylinder with the bleed nipple at the bottom and positioned at 4 oclock so then I can connect up to handbrake linkage and the shoes can then fitted as were originaly fitted to the Wolseley 1500 as per Toms picture of brake assembly I will post pictures once completed, the good news is I will have road tested the car with origianl brakes then the Wolseley fitted both ways, so hopefully will be able to post my results on actual road testing under 3 differnt settings to establish the one that gives optimum brake performance. I am a big believer in road testing to see what suits me and the car. Thanks again for all your comments. Btw Daniel, glad to here you have sorted your camera out, I always keep my phone camera set on low to med setting allowing me to send mms or upload pics to internet, then keep another decent camera set on high for all best quality pics for printing. |
| Rob Newt |
| Hi Rob, Many thanks for your reply. I see now the point yourself, Peter and the Wolseley man were making. Flipping the back-plates to the 'wrong' side and thus putting the slave the other way doesn't change the fact that one brake shoe leads and the other trails. Nor does it change the fact the shoe that fits on the Micram can only fit correctly in one position. BUT, what does change is the position of the brake lining on the leading shoe itself is not the same. This is because the lining is bonded or riveted to the shoe in such a position whereby at one end the lining is practically flush to the end of the shoe while at the other end it's about an inch away from the end of the shoe - I'll call this the gap end. The design of the Wolseley brakes is such that the shoe that attaches to the Micram is meant to be the leading shoe and so that shoe is lined with the gap end engaging first. However, flipping the plates to the opposite side of the car puts the Micram shoe in the trailing position and then other shoe on the non-micram end becomes the leading shoe but is engaging the brake shoe flush end first. There are several alternatives to try and remedy this situation one of which is to modify the shoe. Another is fit the trailing shoe gap end first and not least simply live with the flush end first engaging as the leading edge of the leading shoe. I'm not certain if I've tried both of the latter two alternatives but I think the length of the springs forces you to have the flush end as the leading edge of the leading shoe. The consequences of this I'm very certain of (I hope I'm righ) is that the leading shoe beds in very slowly and very much on the flush end unless you help it by filing it after you driven it a while. Longer term shoe life is uneven and shorter than you might otherwise expect. I don't think there is much difference in braking torque and even from new it will produce 200Kg. Does that sound correct? I still think the flip RH to LH is the way to go because anything else will be difficult to bleed and create an odd route of rigid brake pipe. Finally, it's worth returning to the point that the orientation of brake back plate mounting at the end of the axle is NOT the same on the Sprite/Midget to the Wolsley. |
| Daniel Thirteen-Twelve |
| I have been told the 'gap' was to warn owners that the linings were about to expire completely - and that works cars were sometimes known to compete with 'full-length' linings instead. On the other hand, putting the start of the lining further back towards the pivot point would reduce the 'self-servo' effect. Flipping the brakes means that your leading shoe is being operated by the wheel cylinder sliding, rather than being applied directly by the piston itself. Whether this affects the performance of the brake, perhaps only a drum brake engineer could say for certain (and they may be thin on the ground these days). However, it is NOT how the engineers at Cowley intended it. Tom |
| Tom Coulthard |
| Dumb question time. Aren't W1500 rear shoes a different part number to these M1000 front shoes that we are all using? The shoes that came off of my donor car were the same as the ones in these pictures above but only had a micram hole in half of the shoes. |
| rob thomas |
| OK, some extreme garage-archaeology has resulted in me managing to dig out an axle which I thought was from a Riley 1.5, but turns out to be a Wolseley 1500. The below pic (slightly fuzzy - apologies) is how you would look up at the brake from underneath the car, with the bracket on the axle where the spring sits. As you can see, the bleed nipple is almost at the very bottom of the backplate. Which begs the question: WHAT IS YOUR BLEEDING PROBLEM, DANIEL?? I think you are seeing a bleeding problem where there is no bleeding problem at all. Clearly, since the designers intended the bleed nipple to be at the lowest point on the brake backplate, there is not likely to be a bleeding problem. They sold over 100,000 Wolseley 1500s with this Lockheed brake, and there are no special instructions in the workshop manual, and no complaints on internet chat forums. And why should there be a bleeding problem? It's only a wheel cylinder, with the fluid coming in one end at pressure and the air whizzing out the other through the bleed nipple. It's not like a calliper, where there are internal connecting passageways that can trap air - particularly if the calliper is attached upside-down. (I do hope no-one thinks there is any coarse language in this post. My sister Dolly does hate any coarseness.) Tom  |
| Tom Coulthard |
This is the Wolseley wheel cylinder position from the front
 |
| Tom Coulthard |
| Tom, thank you for clarification of the bleed nipple position. It was me who mentioned the problem with bleeding due to the nipple being at the bottom, however, I did a work-round that allowed simple and instant bleeding without any risk of trapped air. Backplate orientation on the Midget axle is determined by the shape of the backplates anyway. If fitted any other way than what is shown, the plate will warp due to the shape of the pressings when the four bolts are tightened down. |
| PeterJMoore |
This is the Girling brake as it would be aligned on the Riley 1.5 axle
 |
| Tom Coulthard |
| As you can see, the Riley wheel cylinder is positioned slightly higher up the brake backplate. The flange for mounting the backplate on the Riley/Wolseley back axle is aligned in an apparently vertical position (this is the top of the LH side of the axle):  |
| Tom Coulthard |
The flange on the frogeye axle is canted rearwards by about 15 or 20 degrees (clockwise when looking at this LH side):
 |
| Tom Coulthard |
With the Riley brake, there is only one way you can attach it to make the brake rods connect up, which is by rotating the brake forwards to the next position. It ends up quite 'high on the hog' - the Wolseley cylinder would be correspondingly a little lower:
 |
| Tom Coulthard |
| PeterJ - sorry didn't see your post, as I was trying to get all the pics posted. Daniel says he has fitted his Wolseley brakes upside-down because of this phantom problem with bleeding, which changes the leading/tailing shoe, possibly causing the issues he has had with poor bedding-in and uneven lining wear. Tom |
| Tom Coulthard |
| The flat areas on both Wolseley and Riley backplates seem to mate well enough with the flange on the Spridget axle. I suppose you could argue that the extra 'arrowhead' section on the axle flanges is to discourage the backplate from flexing in the vicinity of the wheel cylinder. This extra support is then largely lost, as the brakes have been 'rotated' to fit - more so on the Riley than the Wolseley. However, the many thousands of race and rally miles completed by Sebring Sprites under the most arduous conditions seem to indicate it wasn't too much of a problem. Rob Thomas alludes to an interesting question which no-one has commented on - do the Minor front shoes really fit properly? (Sadly, just because items may have had different BMC part numbers does not necessarily mean they are different, just as having the same part number did not necessarily mean parts were the same!) Tom |
| Tom Coulthard |
| Great pictures Tom. I don't think my car's experienced excessive/uneven shoe wear or taken an age to bed in though I think I helped one shoe with a bit of filing. I don't think I have a record of the mileage but it's certainly longer than a set of front pads (MGB). Good point about the piston action. What I really want to know is whether anyone can get a higher brake torque figure than my car's Wolseley brakes (Spridget or Wolsley) have achieved which would prove there is merit in assembling as Mr Wolseley almost intended. I don't have a bleeding problem but this is because I like to see nipples pointing upwards! All the shoes I have (3 sets) are Wolseley shoes and I intend to get a set re-lined this year. What do the Morris shoes look like? |
| Daniel Thirteen-Twelve |
| Tom, Re. your post above: "With the Riley brake, there's only one way you can attach it..." plus the image you've included. There's something screwy here! I think you may have messed up during your backplate assembly process and positioned the wheel cylinders upside-down. If you compare the photo of the Riley set-up currently on EAO (as posted at the beginning of this thread by Andy Chaffey), with your set-up (presumably from WER 354), you'll notice that the wheel cylinders are vertically opposed! As a result, EAO's wheel cylinder is lower and near enough horizontally aligned with the brake adjuster when positioned on the axle flange, rather than at the higher position indicated in your photo. For my part, I replicated exactly what was present on EAO's axle - as originally assembled by John Sprinzel Ltd., during 1961 - when building up EAO's replacement axle. If I recall, there's a slot in each backplate for the wheel cylinder lever and these should point upwards. See attached photo (taken during the early 1990s) of EAO's original axle/Girling brake set-up. Note: the rebound buffer at the top of the photo. Cheers, Jonathan  |
| J Whitehouse-Bird |
| Jonathan - do you have any bleeding problems?? |
| Daniel Thirteen-Twelve |
| No bleedin' bleeding problems like this. http://www.spritespot.com/gallery/toomanyspridgets/seb_brakes |
| rob thomas |
| As seems to happen quite often with our 'wee gems' (as I've recently seen them described), all this has been getting a bit spooky. But I may have now figured out what has been going on ... The pic I posted above of a frogeye axle is not a frogaxle (ATA 7618). I believe it is probably the later HAN6 axle (BTA 568), after the switch to the twin-piston rear brakes in May 62. Who'd have thought the flange on the axle casing would have changed, and not just the backplate? Below is a pic of a frogeye axle, and I should just say that all the axle-end pics I've posted here have been carefully aligned so that the axle is vertical, as judged from the diff housing. Note that the bump stop bracket is quite a bit off the horizontal, but also that the orientation of the flange is different, with the backplate mounting holes effectively canted more towards the rear of the car (clockwise on this LH side):  |
| Tom Coulthard |
| The pic I posted above of the Riley brake on the frogaxle was actually of a Riley brake upside-down (à la Daniel) on a HAN6 axle. (It was cold in the garage and getting late, and I might have noticed it was upside-down if someone hadn't previously pinched the hand brake lever ... wonder who that was!) Below is a proper pic of a Riley 1.5 brake on a frogeye axle - compare it to the 'as found' pic Jonathan has posted of the same-side brake on EAO. Finally we have a match!  |
| Tom Coulthard |
| Just out of interest, here is the Riley brake on the HAN6 axle. Note how the wheel cylinder and the brake adjuster are in a roughly horizontal alignment, as mentioned by Jonathan in his post, and compare to Jon's Spritespot pic linked to by Andy Chaffey in the third post of this thread. I think we may have another match, though an unexpected and possibly slightly unwelcome one ...  |
| Tom Coulthard |
| Sorry, Daniel - I must have misunderstood one of your previous posts where I thought you were saying you had had bed-in and wear problems. I'm happy to accept that the leading/trailing issue doesn't actually make much difference in practice - though a decent chamfer on the butted-up lining edge of the top shoe must be a good idea. And the sliding wheel cylinders do seem to manage to keep sliding (unlike later sliding-calliper discs which can be hateful things). It was Rob Newt who mentioned the 1098 Minor front shoes - and Martin Ingall (whose post is listed as from 'Neil K') and also Rob Thomas. These are the shoes that were on my Wolseley axle, though I can't be sure they are definitely Wolseley shoes:  |
| Tom Coulthard |
| The odd thing about these is the circumferential length of the linings - it measures a satisfactory 8 inches. This is more impressive than the figure given in the workshop manual for the Wolseley of 6.98 inches and even shades the Riley at 7.66 inches. The w/m for the Minor stops giving lining length for the later models, only giving a swept area of 73.9 sq in for the front brakes - but according to my dodgy maths that's only a lining length of 6.16 inches on a 1.5-inch width. Even odder is the lining length on the shoes of the Riley 1.5 brakes I've posted pics of above. They extend to no more than a measly 6.3 inches and are affixed with 4 rivets instead of the 5 used in Jonathan's pic. These shoes were supplied by JEM in the Eighties, so presumably they were the best available at the time, but why so short? Tom |
| Tom Coulthard |
| Hi Tom, the shoes you have are the same as the 3 sets I have which all came on Wolseley axles. Two sets have riveted on linings and one set have been bonded on. |
| Daniel Thirteen-Twelve |
| Tom, Not only tendentious in matters of detail, but tenacious to boot! Still getting my head around the subtle change to the quarter elliptic axle casing - unbelievable! I wonder how many other MkI Sprite owners have a later casing fitted their cars...or vise-versa? Your early MkI Midget may well feature another related anomoly as a result: 'twin-piston' backplates on an early axle casing - I did an 'upgrade' when it was in my ownership. I'm not at all worried that EAO ended up with a NOS BTA 568 - if anything, the slight anti-clockwise rotation of the backplate probably helped. I'll explain... The previous (original) set-up, using an ATA 7618 casing, had led to problems relating to the handbrake compensator and the large capacity alloy fuel tank fitted to EAO during its conversion by W&P in 1961. Whether by a miscalculation or simple oversight the larger tank, when in position, sat too close to the compensator. Activating the handbrake (and thereby rotating the compensator) caused a serious fouling issue against the tank side. The only solution was to reposition the compensator bracket further forward on the axle casing, enabling the compensator to turn - even then it still fouled the tank. I guess Andrew Hedges didn't have to worry too much about it; besides he sold the car after one season of racing! Subsequent owners, probably oblivious to the problem, continued to operate the handbrake unaware of the damage being caused to the alloy tank. Eventually the inevitable hole appeared and by the time I discovered EAO, someone had 'bodged' a repair (the car had last been used in 1975). I removed the patch to reveal the damage as shown in the following photo - see link: http://www.spritespot.com/gallery/sprinzelsebringsprite/TANK_1 I was unaware of what had caused the hole, as the tank had been removed and placed inside the boot area when I bought the car. As part of the restoration, Len Pritchard offered to make an identical replacement and years later when I eventually offered up the tank...yes, you've guessed - history uncannily, yet accurately repeated itself! However, having unwittingly fitted the later HAN6 axle casing beforehand, I thankfully found myself with a little more space, with regard to the handbrake compensator, than I would have had had I used an AN5 item. I'm assuming those Sebring Sprite owners who retained the original MkI Sprite fuel tank encountered no such fouling problems with the handbrake compensator?! Once again Tom, many thanks for the detail - our knowledge continues to grow! :o) Jonathan |
| J Whitehouse-Bird |
| Oh...and yes Tom, thanks so much for the hand brake levers!!!! Wouldn't have made it to Spridget 50 without them. J W-B |
| J Whitehouse-Bird |
| I said I would post my results for the Wolseley conversion.. So here are my own findings in fitting the 8" conversion. After much debate on which way the slave cylinders go, we have established the way they were intended by Mr Wolseley and the way others have fitted them. After trying the slave cylinders both ways (I wanted to try them both ways for my own piece of mind)my opinion on actual braking efficiency is there is no difference, even if the leading edge is the wrong way round. The main differnce is, which ever way I fitted them the actual brake efficiency was improved by about 20%, (thats without going on the rollers) so IMO a successful upgrade, I realy noticed the difference today after the shoes had bedded in, less brake fade, less pedal travel and hippee a hand brake that works ! Thanks to all who have posted on this thread. |
| Rob Newt |
| Daniel - thanks for that. Are your shoes also the full 8 inches? That's quite an advantage over the Riley set-up if the only Riley shoes available are 6.3". Jonathan - fascinating stuff on EAO. I think the orientation of the axle flange changed because the position of the wheel cylinders changed. It does look like the 'arrowhead' part of the flange is to reinforce the backplate against bending stresses from people yanking on the handbrake (rather than reinforcing the area around the wheel cylinder). With the adoption of the twin-piston cylinder, the handbrake mechanism moves away from the cylinder and sets up on its own, so the cylinder moves round to give it space. It does look like this was the last move it made, as this pic of a late 1500 axle shows the flange in the same orientation as BTA 568 (shackle arrangement for single cable operation of handbrake just visble at lower L of pic):  |
| Tom Coulthard |
| Rob - many thanks for confirming the leading/trailing business makes no practical difference and glad to hear you are pleased with the result. Congratulations on starting this thread, which has strayed into wales/sheep country in its length and probably had Mike P. tearing his hair out at its bandwidth requirements from all the pics! It certainly confirms Daniel's advocacy of the Wolseley brakes as a budget alternative to the Girlings. However, it has occurred to me that the main reason that none of the original Sebring Sprites will have used Lockheed rear drums, was simply because the Girling front discs came as a 'kit' with the Girling rear drums, not supplied through the BMC parts system but direct from Girling through the Donald Healey Motor Co., who I suspect had negotiated an exclusive agreement with Girling, as they had with Shorrock on the supply of their superchargers (for BMC cars - Allard had the franchise for Fords). One further problem with the Wolseley brakes is that they are adjusted from the front, whereas the Girlings adjust from the rear. Not such a difficulty for us now, but for the likes of John Sprinzel, doing non-stop rallies of up to four days and nights duration, having to remove the wheels every time you needed to take up the wear in the linings would have been a major pain. (But if you can use frogeye steel wheels, with their large adjuster holes, it's actually more convenient.) Tom |
| Tom Coulthard |
| Hi Tom, Seven and three quarter inch on the set that's waiting to be sent off for re-lining. |
| Daniel Thirteen-Twelve |
| Hi Another thread revival. Wondering if 5/8” diameter Girling brake rear wheel cylinders (for some Morris Marinas and Itals) fit Riley 1.5 rear back plates for those wanting to go down the Sebring Sprite Girling route (for FIA reasons) but do not want to use the Riley 1.5’s 3/4” diameter rear wheel cylinders. For those who cannot use the relatively more widely available (albeit now rare) Wolseley 1500 8 inch rear brake backplates and set up that uses Lockheed wheel cylinders. Thanks Mike |
| M Wood |
This thread was discussed between 03/03/2011 and 16/03/2021
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