Morris Minor Owners Club

I had a nice weekend away up the Welsh mountains (although forgot to bid on ebay for a Minor / 5-speed belhousing + type 9 box that was cheap - expensive mistake), and to cut a long story short I had a look over Eleanor (Relfy's) brakes and found something not very nice.
One rear drum was caked in oily black slime (axle oil plus brake dust) - so much that it may have wrecked the new brake cylinder and is all over the shoes etc...

The axle oil was changed 1500 miles ago when the car got a well needed spring clean, and I don't remember there being much old oil in the axle.
There was a trace of oil in at the drum / halfshaft flange which was evident when that cylinder was replaced, but as it was so little oil I figured it didn't mean much.

Q's for those people who know their axles:

1) Is the (correct) level of oil likely to have contributed to the leak?

2) If it has a major leak like this, is it worth bothering to fit a new seal or is that likely to just leak? (Or can you fit it a few mm different so it runs on a less worn/damaged surface?)

3) If it needs more than just a new seal, what should be replaced (Halfshaft or axle casing? (or the entire axle )

[The reason I ask about #1 is that the previous owner hinted to problems with that brake but didn't say what - therefore maybe the problem was an old one]

Hello Ray,
I would say that oil level has no bearing on the seal leaking as long as the breather is not blocked. I'm not sure if there is room to move the seal but if you can and the axle casing has worn a groove then that should be OK.
I assume that the leak is from the rear of the hub rather than the face where the half shaft fits, which has a gasket plus a rubber 'O' ring.
If the axle casing is worn and there is no room to relocate the seal there are wear sleeves available for such situations. Basically a precise but very thin cylinder that is driven over the worn section and the seal then runs on the outside of this sleeve. ( I would try a bearing supplier for them)

Alec

I had a rear seal leak on my Sprite due to corrosion/wear on the part of the axle casing where the seal, er, seals (or not). I managed to fix it by a slight skim of "chemical metal" (a kind of filler) carefully rubbed down afterwards so it was completely smooth and round.

The axle oil was changed 1500 miles ago when the car got a well needed spring clean, and I don't remember there being much old oil in the axle.
There was a trace of oil in at the drum / halfshaft flange which was evident when that cylinder was replaced, but as it was so little oil I figured it didn't mean much.

When I last took the rear drums off said vehicle (5th/6th Feb 2005) I too noticed a trace of oil but it was hardly anything......... it looks like it's sprung a leak since then........

Best take it to bits and check what's causing the leak.......

Ray, when my Traveller had it's last MOT (November 2004) I was given an advisory about diff. oil around the left rear brake backplate.
It is possible to position the hub seal so that it runs on a different part of the axle casing, I've done it a few times now on different Minors. From memory don't press the seal in to it's recess as far as it should be. There is a couple of mm leeway.
From what you describe though the leak is quite severe and the surface in way of the seal might be a bit rough. May need a slight rub with fine emery to minimise damaging the new seal when the hub is pushed home.
Could be worth a try anyway - its the simplest and cheapest option initially.
I have found differences in the seals as well. The steel cased items seem to be a better and slightly tighter fit on the shaft around the lip itself unlike the all rubber seals.
p.s. your post reminded me - I've just had a look underneath the Traveller and fortunately it's oil free - so it does work. On this occasion anyway!

RAY, as stated you CAN alter the position of the new oil seal so
that it runs on a virgin area of the axle casting providing that it
hasn't been done before! If the old seal is fully home in its housing
then you stand a good chance. The difficulty is in ensuring that the
new seal is sitting squarely in its new position because it is not being
pressed right in to the housing. I have done this with great success.
If no luck you will have to follow ALECs advice re the sleeve or get
another axle!

Make sure the axle is not OVERFILLED with oil - better to run it slightly low - and as said already, check the breather is clear. Seals get hard and useless - just fit a new one, and a new paper gasket on the hub/halfshaft face. Check also the state of the hub bearing - if it's rattling around, the seal has a very difficult job to do ! Don't see how the brake cylinder could be ruined ? But the linings certainly will be.

Don't see how the brake cylinder could be ruined ?

brake fluid seals should not be contaminated with mineral oil - this can ruin them

Yes - but the seals -especially in the rear cylinders - are well tucked up inside the cylinder bores.

That's true - but the oil had got everywhere and there was plenty of it
I might just do a seal kit, but will worry about the axle seal first.

Give them a wash in Meths - then brake fluid. Highly unlikely the oil could get all the way up into the rear cylinder seals.

To rescue your brake linings you could cover them in meths & set them on fire (burns the worst of the oil out) & then wire brush them.
It's an old trick, it works but they'll never be as good as a new set....
Moving the oil seal as Willie says is successful. Remember to grease the seal before refitting it all so that it doesn't snag on the first revolution or 2 before the oil gets in there...

Oh -- the brake linings WILL be scrap - throw them away ! No matter what you do the oil will always work up to the surface and ruin the braking.

And replacements aren't that expensive. Safety first!