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MG Midget and Sprite Technical - Rear hub woes

I pulled the offside hub yesterday to change the brake cylinder as I believed it to be leaking. What I found was the whole hub and brake shoes liberally coated in axle oil and brake fluid. I've taken the cylinder out and cleaned everything else up and it appears that the axle flange is seeping oil. This presumably seems to be worse as the stud nuts aren't acting as extra tighteners with the wheel off.
Before I pull the axle does anyone know what I'm likely to have to replace. Could I get away with the O ring and gasket or am I likely to need to bull the bearing and install a new oil seal? Having got this far is it worth changing the oil seal and bearing as a precautionary measure anyway?

Just about to have fun drilling and tapping the new brake cylinder per Bill's helpful advice at Stoneligh last week.
Matt 1275 Bucks

Drilling & tapping the brake cylinders?

I haven't heard of that yet.

What's the purpose, to keep them from moving?

Dave
Dave Rhine ('78 1500)

Check your half shaft flanges for run out as well.
Brad (Sprite IV 1380)

Assuming you are replacing the wheel cylinder like for like, the hole should be in the right place. If you pull the pin out, you can tap the hole M5 without the need to drill.
Dave O'Neill 2

Generally the oil from the axle leaks into the drum via the axle flange. This is designed with a gasket and o ring and I have always added a bit of blue hylomar for safe keeping which has generally worked. That said it can leak through the oil seal but it is not a big job to change the bearing and oil seal is it.

The tapping is a very useful mod that BMC owners have been doing since the original circlip was replaced by that terrible modern clip in use today. I have never managed to get one of those diabolical clips to fit since their invention so tapping is my prefrence. However I now have rear disks so aint a problem any more. :)
Robert (Bob) Midget Turbo

Matt,

Considering how much of a b*TCH that brake cly is, Id heavly suggest rebuilding the whole side,,,bearing, seal, paper gasket...the whole sha-bang.

Id hate to JUST FIX the problem and have something else go wrong in that aera in the next 3 months

Prop
Prop

Matt,
Is the coutersunk screw that holds the halfshaft in missing? I had a similar leak soon after buying my car and it turned out somebody had just shoved a load of silicon in the joint with no screw holding it in and no locking tabs on the nuts. New gasket, o ring, screw and locking tabs sorted it after removing all the crap.

Trev
T Mason

Bob,
what do you do for a hand brake?
Brad (Sprite IV 1380)

Brad I used MGF rear calipers which have a handbrake function on them. I simply had to make a double pull link and fitted two handbrake cables.

Trev I assume your car has wire wheels? Steel wheel cars only have a screw and then relies on the wheels and wheel nuts to hold it flush
Robert (Bob) Midget Turbo

Thanks folks.
Sounds just like the O ring, the gasket a smear of hylomar then.
More shopping.......think I'll get some more for the other side just in case.....
Matt 1275 Bucks

Bob
Yes I have wire wheels. Didn't think to obviously mention no locking tabs if you have steel wheels.

Trev
T Mason

Last time I replaced my O-rings and paper gaskets, I used the lug nuts and a few washers to draw the flange tight against the hub, and then tightened the countersunk screw. I figured that would make for a better initial seal than simply depending on just that little screw to pull things together before I remounted the wheels.

-:G:-
Gryf Ketcherside

Matt - check the mating faces really carefully. The smallest raised 'bruise' can hold them apart, and those are too easy to make if you (or a P.O.) prised the old hylomar-stuck joint apart by whacking a screwdriver into the gap.
Nick

Nick
.......and guess what I was going to use to get them apart tonight........
Thanks as ever for the help one and all. Just waiting for the postie now.
Matt 1275 Bucks

Prizing off the drum can help stress the o-ring/gasket seal; this is esp bad if the axle is tilting so the diff oil is already against the gasket. Some minutes spent prizing off the drum under these circustances can let oil onto the shoes that wasn't present beforehand...

A
Anthony Cutler

Anthony,
That makes total sense but my hub and brake shoes were so impregnated with diff oil and brake fluid that I'd be surprised if I had any retarding effect whatsoever! My friendly MOT tester let me off last year so I thought I better get it fixed befor the end of the month.
Just spent a happy couple of hours practicing my until now non existant metal working skills and now have a nicely tapped new brake cylinder ready to be bolted up tight.
Surprisingly chuffed!
Matt 1275 Bucks

glad it worked for you Matt

did you find a "bottoming" tap or sculpt your own?

and what size did you make the thread?

how deep too?

we must KNOW!
bill sdgpm

Bill,
Took your advice and sacrificed the tapered end having started the thread. As I had a few long M5 bolts knocking about I drilled out to 4.2mm about 1.3cm deep and then cut down my bolt to suit. Forgive me for I have sinned and gone metric! I'd like to say "piece of cake" but I'm waiting until my new O ring arrives before I pull the half shaft and reseal before fitting everything back up. I'm binning my brake shoes as they are thick with ooze. Ah and more expense as it suddenly dawns on me I'd better buy an easibleed or similar. I fear I won't have the patience with my attractive assistant to do it the old fashioned way!
Matt 1275 Bucks

Matt,

Not that I'd recommend the procedure but I've spoken to a few people in the past that said they'd cleaned up oiled shoes by soaking them in petrol and lighting them to burn off the contaminants to good effect. May have been safer in the days of riveted shoes. Shoes are cheap these days.
David Billington

Hi david

BTDT many years ago after Scimitar Coupe failed MOT; passed a couple of hours later on same shoes...

A
Anthony Cutler

£10 for a pair of new shoes or singed eyebrows? New shoes please! Can't have too much peace of mind when it comes to the anchors (or the eybrows for that matter)
Matt 1275 Bucks

Ah well, think of this as areal investment, rather like grinding a taper OFF a tap. Easibleed will out live you and work for every car you need to work on hydraulics on forever. Used mine again last weekend when I had to remake the hydraulic pipe connection that leaked and robbed me of clutch action driving home from Stoneleigh.

re-make pipe joints
open remote bleed screw
fill easibleed reservoir with DOT4
Fit to dual cylinder cap, tightly
connect air pipe to tyre valve
watch bubbles flow out of clear pipe into old fluid tin
tighten remote bleed valve

have cuppa, job done!

easibleed rocks man

but do recheck tyre pressure after
bill sdgpm

The only grumble I have with Easibleed is that the threaded bottle cap is very nearly, but not quite, the same thread as a 1 litre bottle of DOT 4. If they had used the same thread it would save the filling and transferring of fluid which always carries the risk of introducing air bubbles. A small thing, but a different design of cap would have been so much better!
Guy Weller

A small point though Guy

DOT4 bottles are not quite as likely to be able to resist an accidental overpressure as the Easibleed bottle

I don't fancy much of an overspray of DOT4 round my engine compartment, messy as it already is :(

My Easibleed bottle/reservoir wall is about 3/32" thick
bill sdgpm

I find that it is a good idea to reduce the pressure in the tyre used for powering the EeziBleed to 20psi or thereabouts before starting. Likewise fond of hooking everything up without any fluid in the bottle, verifying that I have a good seal at the M/C, THEN releasing the pressure and adding fluid to the bottle. Saves the occasional spray of brake fluid (aka paint stripper extraordinaire) in my not so clean engine compartment.

Dave,
I also drill and tap the roll-pin hole on the back of the wheel cylinders. 10-32 works well for those of us not overly interested in mixing metric into our Spridgets (future DPOs, OTOH...). I have found that, even when the E-clip is correctly in place, there is frequently enough motion permitted to allow the brake drums to cut through the dust covers of the slave cylinders with less than desirable results. Pulling the roll-pin and tapping the hole from it took care of this for me.
David "besides, how often do I get to use a tap?" Lieb
David Lieb

A stitch in time saves a f*** of a lot of swearing.....

Reassembled everything tonight. Drained the axle, pulled the half shaft, new gasket, O ring etc, etc. refilled the axle. Bolted up my new cylinder. Couldn't get the brake line connector to thread....unbolted cylinder....started thread on brake line..... rebolted cylinder, tightened up brake line, fitted bleed screw. Got new brake shoes out of box, looked at piccy in Haynes......sod it, forgot to swing handbrake linkage back into place across backplate! Doesn't fit between hub and cylinder. Undid bleed screw, loosened brake line, undid my nice new bolt! Removed cylinder, swung linkage into place, back on with cylinder,etc, etc.
Thank god I tapped the thing as I think getting the circlip off and on three times would even have the Pope excommunicating all BMC engineers!

All back together now. The handbrake pulls the new shoes on nicely but I haven't bled tthe brakes yet as the new shoes are still to go on the other side and guess what? My branch of Halfrauds hasn't heard of an Easibleed! Mind you they didn't seem to know what EP90 was either! "What car's that for then?"
Going to bed happy tonight!
Matt 1275 Bucks

easibleed is by gunsons

get the (un)trained idiot to look in their online catalogue for it If you have their trade card it will be cheaper

then when he finds it tell him "ta, now go away and play with bikes again, I won't disturb you again!"

just about all Halfords staff is good for these days is checking the chain on yer bike (yes I am bloody angry with Halfords morons this week)

Maybe go to "Joes Spares" and see what kind of deal they can get for you, or order through Partco or any other motor factors

bill sdgpm

This thread was discussed between 28/02/2010 and 03/03/2010

MG Midget and Sprite Technical index

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