Hub Seals...what did I do wrong?

[94rangie]

Last year the 88 did not pass inspection due to leaky hub seals. The brakes were coated/soaked in 90W. I replaced all the seals and one race (the only one that had any wear/corrosion.) At the same time I replace the brake cylinders, shoes and flex hoses.

Today I replaced the master brake cylinder. When I went to go bleed the brakes I found both passenger brakes soaked in oil again! The worst one was the one I replaced the seal and race (right/rear.)

Right rear: I don't think I put any sealant under the race, could this be my problem?

Right front: I guess I should have replaced the race along with the seal?

Or am I missing something else?

Of course the 88 is out of inspection and I need to get it on the road so I can replace the heater core and blower in the Rangie. Maybe I'll get to it by spring.

Regards,
Larry M.
'72 IIa 88"
'94 RRC SWB

[SafeAirOne]

Things that readily come to mind:

1) Are you certain it's gear oil and not brake fluid?
2) Are the spindles worn/grooved where the oil seal rides?
3) Is the oil seal misaligned or damaged?
4) Are the axle vents unclogged and working properly?
5) Race sealing is not an issue--the oil has free passage through the bearings for lubrication. The only access differential oil has to the brake drum SHOULD be past the oil seal on the inner part of the hubs if I'm not mistaken.
6) I doubt that this would be the issue, but I always apply non-hardening gasket sealant to the mating surfaces before I press new oil seals in.

[jopa]

Check the axle vents to make certain they are not clogged...a non operating axle vent will result in oil escaping past the hub seals...does not mean your hub seals are shot...means pressure builds as the diff, oil, gears, etc heat up and has to expand somewhere...Good luck- John

[sayers]

Is there only one vent on the axle and is it on top with something like a dust cover over it ? thanks

[I Leak Oil]

Yes.
Jason T.

[Andrew IIA]

Is there only one vent on the axle and is it on top with something like a dust cover over it ? thanks

Those little buggers are notorious for getting gunked up and sticking closed, causing pressure build-up, which will cause a leak somewhere (usually at the pinion seal for me).

Remove the vent with a wrench and clean it up well (soap/degreaser and hot water worked for me) until the little ball in it rattles freely back and forth. Reinstall.

Lots of people (me included) get rid if the pesky things in favor of vent tubes that extend up high somewhere and do not have any moving parts to get stuck; often seen in 'wading' kits, but useful in all conditions.

Good luck !

Andrew
'63 SIIA 88"

[willincalgary]

As per Andrew IIA's comment. I had both seals leaking on the rear axle after driving some distanct to warm the oil. I replaced the breather with a tube and the leak went away and never returned. Cheap and easy.

[sayers]

Thanks for the great advice, gentlemen.

[94rangie]

Check the axle vents to make certain they are not clogged...a non operating axle vent will result in oil escaping past the hub seals...does not mean your hub seals are shot...means pressure builds as the diff, oil, gears, etc heat up and has to expand somewhere...Good luck- John

I checked the breathers last year when I first found hub seal leaks, and they appeared to be operating properly. I agree I should simply remove them and install vent tubes. Any idea what the thread size is?

Someone else mentioned I should make sure it is oil and brake fluid. I did check that too.

Cheers,
Larry M.

[siiirhd88]

I checked the breathers last year when I first found hub seal leaks, and they appeared to be operating properly. I agree I should simply remove them and install vent tubes. Any idea what the thread size is?

1/8 NPT pipe thread fittings fit just fine. I used 1/8 NPT to 1/4 compression fittings with a flexible plastic tube. Leave enough slack in the chassis to axle tube to allow for articulation.

On both 109's I plumbed the axle, transfer case, OD and transmission vents to a common line run into the engine compartment. I added a 'T' to the vacuum hose going to the brake booster and installed a needle valve, to which the common vent line attaches. I set the needle valve to pull a slight vacuum, which has minimized oil leakage and also the 90 weight odor from the vent lines. For wading I close the needle valve.

Bob

[Linus Tremaine]

If the port on the axle tube is close to 1/8 npt that is because its probably 1/8 british pipe. Just for basic stuff to stick in the back of your mind, 1/8 british pipe is 28 threads per inch while 1/8 npt is 27. Also, british pipe measures a smaller nominal OD. So, 1/8 NPT will go in a 1/8 BSPT hole but not the other way around.

[yorker]

I checked the breathers last year when I first found hub seal leaks, and they appeared to be operating properly. I agree I should simply remove them and install vent tubes. Any idea what the thread size is?

.

The same as your brake system's flex lines.

[dansalisbury72]

do any of you happen to have any pictures of the vent tubes installed? I also have one brake (right front) that is covered in oil, so I assume that I have the same issue.

thanks...

Dan