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MG TD TF 1500 - Rear Oil Seal Leak Cause?


For a while I've not been happy with my brake response and finally am replacing all wheel cylinders and brake shoes. Got the fronts done and came upon a surprise in the rear.

After pulling the one rear drum I discover the insides are oil soaked, .... but not rusting!(humour attempt)

The oil seal looks fine, but somebody please tell me how the seal can prevent oil getting past that inch and a half spacer that's cambered on its outside, particularly when the spacer just winds freely on the axle!

I assume that when the rear end (diffy)has the proper oil level, the amount of oil in the axle tube is below the inner diameter of the rear oil seal, and can't leak out.

I say this because I have been in the habit of jacking the car up in the middle of the side frame (tilting the car up on its side) to do oil filter changes and chassis lubes.

In this situation, I'm thinking that with the car tilted as much as 25 degrees on its side, oil would fill the axle tube and leak past the seal.

Am I on the right track here, or do I have a leaking seal?


P Burgess

The tightned hub nut/drum taper should tightly squeeze the split collar into the bearing race. A loose nut/drum will allow the spacer to move outward, allowing oil to leak between the spacer and axle shaft and into the drum. Oil can also leak between the outer of the seal and the housing. I use a very thin layer of blue Permatex on the outer edge when installing the seal. Make sure the nut/washer is squeezing the drum, and not bottoming on the axle splines. Of course the sealing surface on the tapered collar must be perfect. Make sure the axle breather hole on top of the left axle tube is open as well. George
George Butz

Hi George, I read about that breather hole earlier on the board and went to look for it with no luck finding it.
Not on the left or on the right tube . Could you or maybe somebody else help me a bit here ?? to find it!! picture perhaps. Thanks for your time
Gerard Hengeveld

Look under the inner metal clamp holding the brake lines to the axle. I've been told (and I believe) the factory placed the metal clamps over the hole to prevent dirt from falling in to the axle.
D. Sander

George, here's an image of the vent as seen from the top of the left rear axle. Bud

Bud Krueger

Thanks Bud ,

Gerard Hengeveld

My advice is to block up the vent hole (it is an invitation for dirt in the axle)
Instead drill and tap the filler plug and fit a midget or "B" breather.
Ray TF2884
Ray Lee

gene, did you have the drums turned...or at least check them for runout? as you may cylinders and pads do little if the drum faces are not true. regards, tom
tom peterson


Many thanks for the info on the breather hole. I found mine absolutely plugged. It was most likely the cause of oil being pushed past the passenger side axle seal, rather than my car tilting activities to make oil filter changes easier. But I think I'll refrain from doing it in the future.


Thanks for the heads up, but several seized wheel cylinders, and one rear brake assembly dripping oil from every part, take top spots for being the problems. A close inspection of all 8 brake shoe shows very even wear patterns over their faces, except for the one rear set which were hardly worn at all. I betting the oil impregnation kept that set looking near perfect and new.

Now, all I need to do is replace the two rear axle seals, reassemble both sides, ... (it never fails) replace the short brake line to the left rear wheel, which twisted off on disassembly, and bleed the system.

All the old shoes are off to be recycled.

P Burgess

This thread was discussed between 25/08/2012 and 26/08/2012

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