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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGA - Remote Brake Booster

I have just bought one of the above with an installation kit for my 1600 and also new Mintex disc pads ( some recent good discussion on this site re latter ) . I intend to start using the MGA as an every day car and wanted to uprate the braking system as I have never tackled it before...and my wife may also be using it I am aware that the booster will not improve braking power ..just lessen the leg effort more in line with modern cars. The booster is VH44 size ie 7in dia and 820psi output. My next decision is where to put it . I have a heater/blower ( and need it in Victoria ) and no radio ( could never hear it so out it went years ago ). I see two choices so far ( from Barneys site ) ..inside the fender or under the dash and would really appreciate comments on these and any other locations used or considered and any lessons learnt.
Neil Ferguson

one vote for under the dash Bob
Bob Walker

Neil, I fitted mine on the inside of the front wing, behind the splash panel. I also fitted it to be below the height of the master cylinder (The instructions said so), so i guess an under-dash installation might not achieve that.

regards
Colin
Colin Manley

This is mine. Fitted behind the radio, under dash. Works really well.
Bruce


Bruce Mayo

Neil
you will like the Mintex 1144 pads, they worked on my car a treat, let us know how you rate the servo once you have fitted it. A servo is on my to-do list somewhere much further down than the supercharger! :-)

Are you in the group bringing their MGAs over for the Lands End John-o-Groats run next year? If you are I am looking forwards to meeting you and seeing your car. If not, I hope to visit Oz in a year or so, after I retire and I will do my best to look you up.
Colyn
c firth

Bruce...that does look neat and tucked away ..and with a radio still there ( I have no radio). Can you advise me the external dimensions of the booster you used? Have you had any problems with the unit?..in particular re Colin Manley's comment about the relative height compared to the master cylinder.

Colyn...will not be coming for that Uk journey....but would welcome catching up when you are in Oz...I will post results from fitting the booster .
Neil Ferguson

Hi Neil. Sorry about the late reply - been in Birmingham NEC for the Classic Car show today. Amazing selection of beautiful old cars. The brake servo is a Frenos Iruna Tipo A1, used in many vehicles and still available from SVC and others I believe. If you google it you will get all the details and dimensions better than rough measurements from me. It works just fine, really makes the pedal light and no problems that I have ever experienced from its position. Colin may be right but I have doubts as my behind- the-dashboard location is certainly not the first I have heard of. All done by the PO for which I am grateful - it transforms the car!
Best
Bruce.
Bruce Mayo

Bruce....that is quite a unit .first time I had heard of the company. It also packs quite a belt ...output pressure is 3 times input ( presuming you have sufficient vacuum). They have packed it all in a small volume ..only 5.5 in dia so your PO made a great choice and probably exoensive.
My unit is a PBR VB44 type and generates about 1.8 ratio according to bumf .....so hope it works well. It will be a few weeks before I get around to installing ...it has not even arrived yet and I am 700km away from my beloved ...
Neil Ferguson

Bruce...Just looked more closely at the charts for your wee beastie booster and at a vacuum of about 23in the ratio input to output pressures is 2.5 ( for lower input pressures ) ranging up to 2 at the highest rating.....so average about 2.25 .That makes me a little more optimistic that my PBR unit will give good improvement in pedal pressure.
Neil Ferguson

Neil I just fitted a VH44 to my MGB and find it just right in feel. Not neck snapping but it feels approx 50% less effort and smooth application. I have the greenstuff pads and found them no improvement over OE.
Fitted mine near, and in front of the master cylinder so the original pipe from the master could be used. I had to use adapters for the booster outlet as the supplied fittings would not seal. Went to 1/4" pipe for the outlet. The unit is pretty compact and does not look out of place. Denis
Denis4

A pic of the VH44 on my B Denis


Denis4

Wish I had that much room in my A. ..but your comments re performance are reassuring..thanks.
Neil Ferguson

Neil
How are you planning to tap the Judson manifold for the vacuum outlet?
dominic clancy

Dominic..Long way away from the car right now so have not had the chance to make the judgement.... any recommendation?
Neil Ferguson

The brake booster on Barney's site is from my car. I used an Armstrong unit and it is in the fender well behind the passenger side. It is hooked up to the petrol pedal rod on the passenger side in left hand cars. I designed it so it would not show. The only tell tale sign is the stainless steel pipe on the bulk head wall in the engine compartment to the fender wall for the vacuum pipe from the carb to the booster. I pulled vacuum from a vacuum port on the Judson intake manifold.

Jeff Becker
Long Beach, California
JEFF BECKER

jeff..I do not follow the reference to the petrol pedal rod...please amplify?
My Judson inlet manifold is a Neil F Design made to accomodate a single larger SU in place of the Holley ( Dominic did similar with his own manifold design)..so non standard).
Neil Ferguson

Jeff..I meant to ask a few queries.

..What is the outside dia and length of your booster?
..What is the pressure ratio inlet/outlet?
..How does it perform ?
Neil Ferguson

Neil my B has the Moss supercharger and I use the tapping in the plenum chamber. The one way air valve on the VH44 has no problem controlling the boost. If you wanted to be extra careful Moss sell a valve for the vacuum line that they recommend for boosted brakes with a supercharger. #150-171 Denis
Denis4

Denis..I intended to simply take a vacuum connection off the Judson inlet manifold ( between the SU and the Judson). I did not envisage any particular issue in using a supercharger and intended to use the check valve on the VH44 shell to keep good vacuum on the booster when low or no vacuum on the manifold . Could you amplify re. the complication you refer to ( or Moss refer to re their supercharger) and why they consider another valve is necessary in the vacuum line?.
Neil
Neil Ferguson

Neil I am not using the Moss valve and find the VH44 valve works well but Moss in their fitting instructions say to use their valve with power brakes.
It may be that the MGBs that came fitted with power brakes had a valve that was not up to the job. The tapping for the power brakes is is in the Moss plenum chamber, but before the blower, as you propose, should work as well and not be subject to boost. I also wonder if the Moss valve is used to preclude fuel vapor from the vac pipe under boost? Anyway you dont need one with a pre SC fitting. Denis
Denis4

I would suggest a tapping in the underside if the NF/Clancy manifold as it would avoid bible pipe runs up top, and avoid tight bends that are otherwise necessary to clear the bonnet / hood.

The tapping needs to be large enough for the vacuum to be effective, so probably needs a 1/2" diameter on the pipe, so the tapping needs to be larger. I would drill and weld a fitting for a ADU1402 which is the servo valve for an MGC, and then the fittings would at least be available from MG suppliers in the future.

I'd be particularly careful to use a valve at that fitting instead if a simple tapping, because if there is any backfire on the SC, I would be worried about the effect on the servo diaphragm
dominic clancy

Dominic..sounds sensible especially as I am leaning towards putting the booster under the dash on the pax side ( UK/Oz drive) as suggested ( and done ) by Bruce and others so the vacuum hose only needs to be short and almost straight aft through the bulkhead.I have no radio so plenty of space. Your comment re check valve on the manifold is the way to go as well.
Two extra thoughts ..
..the bottom tapping may allow fuel to enter the hose.
..I was also looking at installing a booster reservoir bottle with a check valve between it and the manifold and this would allow a smaller fitting/hose and many more strokes of the brake with boost if vacuum disappears. Conservative and a bit like belt, braces and a nail though the navel to keep the trousers up! I am that sort of engineer!
Any thoughts anyone ?

Denis....I now understand where the tapping is and why the valve ( also looked it up on the Moss installation instructions via google.). It is good protection for the booster and also the same as per Dominics suggestion above.
Neil Ferguson

Neil
The fender side of the manifold where the original has the vacuum fitting for the oiler would then be the only option for the fitting, as otherwise you are too near rhe chassis. This would probably make installation a pig, because I have always fitted everything to the Judson before the final mating up to the head manifold. Here I need a helper to thread the three bolts into the blower casing. But I dont share the concern about fuel that always sits in the inlet manifold if you let the threaded valve sit slightly proud of the bottom of the inside of the manifold. In my experience in it would only need two or three mm protrusion to always be above the level of residual fuel.

dominic clancy

Dominic..that is a good approach ..I am also of the opinion that a wee bit of turbulence ( resulting from such a lip) plus high velocity is good for fuel/air entrainment.I kept the manifold cross section close the original manifold to keep velocities up... Thanks...
Neil Ferguson

Neil, I have a nice neat little vacuum tank from a Jag that I intended to fit under the car apron forward of the radiator, however after driving the car I had second thoughts as even with the engine off you get a couple of good brake applications and then the brakes are still as good as OE with no vac. Now after thinking about it I may still go ahead with it as this tank has its own one way valve and may protect the booster from vapor. Are you going to Rob Roy on sunday? Denis
Denis4

I suspect too that you will not get best vacuum performance with a smaller diameter hose to the servo. I don't go along with the reasoning on that a smaller diameter will give you a longer engine-off boost performance.
dominic clancy

Dominic....One can buy small vacuum cylinders which fit into the vacuum line ( around $100) and have a check valve between the cylinder and the manifold. In normal operation you do not need to rely on the manifold as a vacuum reservoir when you operate the brakes( in addition to booster vol.) so the size of the hose between the reservoir and the manifold is not so important as the demand comes from the cylinder and is at the same or higher vacuum as the manifold . The same principle applies in the event of manifold vacuum reduction or loss. Think I will do some calcs on alternatives and see if I can persuade myself I am not complicating the planet.
Neil Ferguson

Denis, on an A with a Judson and a heater there is almost no room left at all under the bonnet, the booster can only go under the dash or behind the wing
dominic clancy

see picture


dominic clancy

Dominic..I know that vision too well..room just for bruised fingers

All..My Booster arrived today ..all I need to do now is drive 700km to get to my mga.
I attach a pic of the two vacuum arrangements I am considering.
Fig 1 is the bog standard..interesting to note that the hose provided isapprox. 9mm id and the end fitting ( for the manifold ) seems to be a 1/8in NPT (or similar) requiring a tapped approx. 10mm hole. Will sort such in detail when I get my taps/dies.
Fig 2 shows the use of a vacuum reservoir with an additional check valve between it and the manifold.
I did some very rough volume calcs and came up with..

...Stroked volume of Booster 7in diaphragm..somewhere between 40 to 80 in3
...Volume of the vacuum reservoir 43 in3

The posts on various blogs seem to indicate that the booster without reservoir gives 2 to 3 pedal strokes after the engine is turned off.
The reservoir would therefore seem to be potentially able to deliver the order of an addition 2 strokes max ie 4 to 5 ...and also make the booster action a lot more independent of manifold vacuum variations.
Seems worthwhile for a conservative like myself .



Neil Ferguson

Jeff...presented my booster to various spaces in the car and decided that the best ( and probably only ) way was to fit it in the fender cavity. Bruce's arrangement under the dash looks neat but the OD of my booster is larger than his and it does impinge on pax space. Will be a few weeks before fitting .
After brake fluid total replacement (a high spec DOT 4) and seeing that the existing disc pads had loads of meat left decided not to replace pads as the brake system really performed well on the long drive.
Neil Ferguson

Neil the findings with my VH44 on the B after a couple of longish trips are very good. As for feel under very light application it is the same as before, but comes in progressively with more pressure. My kit came with 3/8" hose as are the fittings. Reserve is good with about 1+1/2 at boost level then OE so it will still stop. I do have a neat jaguar vacuum chamber and may fit it one day but you would need a catastrophic engine failure to need it. I have the green stuff pads which I was not keen on but they work great with boost. Yesterday I fitted a set of Goodrich braided hoses just to be safe and they gave the brakes a better feel. I was not impressed with the vacuum hose that came with my kit so I replaced it with a better quality. The difference now is that you have a more confident feel in the braking of the car, even if a panic stop is still the same. Denis
Denis4

Denis...Good to hear about the VH44 performance.I agree re the vacuum hose .It looks poor quality chunese stuff. I roughly measured id of my hose and it was about 9mm ..so probably 3/8in. I will also be upgrading. Did you use the copper pipe supplied and any advice on how to bend/form form to fit and get good seals with the ends. Any idea where I could get bulkhead fittings to the hydraulic pipe to take it through to fender cavity.
Neil Ferguson

Neil, you can get all the bulkhead fittings from Automec in the UK, which is where I sourced everything, including the copper nickel pipe (wait until all the anti brigade hear this, as this pipe, although so called not approved for use in Australia is actually used on most luxury car imports..Audi, Porsche etc).
Gary Lock

Gary....many thanks...I've been on a the net a few times looking for these but no luck so far..
What booster did you fit and what threads and sizes were involved?
Neil Ferguson

I was lucky in that the pipe from the master to the 3 way union fitted the inlet of the VH44 and only needed a slight bend but the outlet pipe from the booster was a different matter. I had a pipe made up at the local hydraulic shop with the correct nuts but it leaked bad. I am now sure the booster is designad to have adapters. I was also lucky to have an old lockheed booster under the bench with adapters for 1/4" pipe so I had the shop make up a 1/4" pipe and used the adapters with copper washers, he even lent me his pipe bender to fit it. He made it out of bundy tube which is like a copper lined steel pipe strong but bent beautifully. I have been out of the motor game for a while now but I have an idea RWC testers frown on copper pipe. The pipe that came with my kit had what looked like copper coated steel and very soft. A good hydraulic shop (being in the sticks there is one in every town)can supply quickly. The 1/4" pipe is much more robust and his double flares looked much better on the larger pipe. Denis


Denis4

Neil, the booster was a Moss item, which are a Lockheed clone. The Automec fittings were:
Brass union 3/8 24UNF male Part HU1
Brass Union 3/8 24UNF female Part HU1A
Brass bulkhead fitting M10 x1Part HU106
Brass union M10 x 1 female.Part HU2A
CuNife coil 25ft. Part CNF316

Automec do sell singles, but their website is undergoing update at the moment, and only shows packs of 10. Just email them info@automec.co.uk
Gary Lock

Great detail..ta!
Neil Ferguson

Gary..the existing lines are 3/16in ..are all these fittings for 3/16 cupronickel pipe?
Neil Ferguson

Yes, these are the fittings for the 3/16" CUN pipe.
Gary Lock

Denis
Your ign. coil wants turning up the other way before it dies -- willy
William Revit

Willy I know its the opposite way than most Bs but will work as well that way, is easier to see and even slightly more reliable being oil filled, in the event of a leak. Do you know something I don't???
Denis
Denis4

I've always been under the impression that they go the other way up OR flat on their side with the primary terminals accross horizontal
The reason being that where the primary coil connects to the posts needs to be in the oil or the connection can overheat and burn the coil wire off the post
Old story told to me by an old fella years ago but he swore it to be a fact cheers willy
William Revit

This thread was discussed between 14/11/2014 and 10/12/2014

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