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emicola
09-07-2017, 07:47 AM
Hi Everyone, I need some help with a leaking hub seal on my 1964 SIIA 88. I have replaced the left rear hub seal twice and now it needs to be replaced again. The first time I replaced inner/outer bearings and races, the second time I replaced the hub seal race. The axle breather is brand new and the hole it screws into is free and clear as well. I thought that maybe the bearing races weren't driven all the way into the hub preventing the hub seal from working properly. This is not the case, I ran a feeler gauge around the perimeter of both races and I can't find any gaps, the races are seated completely into the hub...... What's next, the hub??

lumpydog
09-07-2017, 08:43 AM
Hi Everyone, I need some help with a leaking hub seal on my 1964 SIIA 88. I have replaced the left rear hub seal twice and now it needs to be replaced again. The first time I replaced inner/outer bearings and races, the second time I replaced the hub seal race. The axle breather is brand new and the hole it screws into is free and clear as well. I thought that maybe the bearing races weren't driven all the way into the hub preventing the hub seal from working properly. This is not the case, I ran a feeler gauge around the perimeter of both races and I can't find any gaps, the races are seated completely into the hub...... What's next, the hub??

Very likely internal pressure build up - forcing the oil out. Remove the breather from the axle and clean it thoroughly with Brake Clean or some other solvent that will ensure it is clean and functional. As you remove the breather, listen for air escaping. Just because it's new doesn't mean it's working...

One other thought - in the Series 3 manual, they changed up the guidance on installing the distance collar (what you referred to as the hub seal race) and call for the use of a sealant. https://photos.app.goo.gl/RVOozV4Exq6zt2y13 Oil can get through there without the sealant.

Where is the leak apparent? Dripping from the brake backing plate? Hub cap/cover? Drive flange?

emicola
09-07-2017, 09:45 AM
Thanks for responding! It's leaking down the backing plate into the drum, the grease/oil is clearly coming from the hub seal. The hub cap is dry, no grease/oil leaking inside and the breather rattles around freely (it's still clean and shiny). The last time I replaced the distance piece I used anearobic sealant, whoever installed the previous one didn't used anything. I was sure this was the cause of the leak the last time I pulled the hub apart. I'm thinking of swapping the left and right hubs to see if the leak follows the hub.

lumpydog
09-07-2017, 10:04 AM
Are you using permetex or some other sealant around the outer circumference of the hub seal? That leaves only the mating surface between the race and the seal to be suspect if still leaking...

Are you seating the seal too deep into the hub? It should be flush with the hub's outer rim. Driving it in too far means the rubber seal's inner circumference lip is not mating to the race's outer circumference.

https://photos.app.goo.gl/94RiaJ9XT9XcQYnp2

emicola
09-07-2017, 10:42 AM
Yes, I used a Indian Head on the outside of seal and there was no grease/oil between the seal & race when i pulled it apart, just dried Indian Head. My seal is flush just like the picture.

lumpydog
09-07-2017, 01:20 PM
Damn - you've covered a lot the typical misses.

Bit of a Hail Mary here: You sure it's the hub? Given where it's coming from, you may be leaking hydraulic fluid from the wheel cylinder...

I've misidentified this same leak from the same location... In my case it was the reverse. I thought the leak was the wheel cylinder - but it was the hub that was leaking (my distance piece/race was corroded and would quickly compromise the seal's lip).

Easy way to check is to pull back the rubber covers at the ends of the cylinder and see if there is fluid in there.

emicola
09-07-2017, 02:48 PM
I've already crossed that one off the list. I replaced all my wheel cylinders with genuine parts a couple months ago and they're still dry. I'm going to swap the rear hubs to see if the leak moves to the other side, if it doesn't then I guess it has to be the spindle.

lumpydog
09-07-2017, 03:23 PM
Agreed - process of elimination