Wheel seal leaking

[Bigmon]

I have a left rear tandem wheel seal leaking. Here is the story.

Had a new one and brakes put in. Lasted 350 miles and started leaking again. It was under warranty so had it fixed again. Got 1000 miles and no leaks.

Truck has been parked for a week and notice about 2 spoons full of fluid on the top of the rear bottom brake shoe. Checked around and got a few suggestions.

1. Put new one in and see what happens.
2. Put sealer in the axle and see if it stops.
3. Axle spindle may be damaged causing seal to malfunction.
4. Fluid may just be left over from previous leak.

Any thoughts would be helpful. BTW...truck is a 2001 Freightliner Classic with 800k.

[allan5oh]

At the last seal change, they should've cleaned any oil leftover, if not, they're a bad shop.

It's possible your vent is plugged, and if that's true you need to get a new vent, then change the seal. Otherwise you'll keep blowing seals.

[Bigmon]

Thanks Allan,

Where is the vent? I think Steve had this same problem last year. The vent thing sounds familiar.

[Jumbo]

On one side on the top of the axles. Looks sort of like a mushroom. I usually pull up and down and turn the top once a month or so on mine. It doesn't take much to make them stick and not breathe.

[allan5oh]

It can be a tube as well.

[NotSteve]

I got faked out and maybe your seeing the same thing.

I had a leaking seal so I replaced the hub. Everything was fine and then after being parked for a while and running through rain I noticed an oil streak running straight down so I replaced the wheel seal again. Same thing.

Then it dawned on me. If the seal was really leaking it would be spraying all over in a circular pattern and not just one straight oil leak to the ground.

I didn't clean the oil out from the original leak and when water got under the chrome hub cap it washed a little oil out and dripped straight down.

[Bigmon]

I'll check it out tomorrow when I have time. The guy let me stand there and watch him replace the seal. He washed everything off except the hub cap.

[Bigmon]

It was getting dark out and I couldn't find that mushroom thing. All I saw was a fitting that looks like the ones you put grease into. Does anyone have a pic or diagram?

[heavyhaulerss]

you may need a wear ring put on before your new seal is installed.

[Kranky]

you may need a wear ring put on before your new seal is installed.

Stemco seals use the wear rings.

National and C/R do not.

[bob h]

It was getting dark out and I couldn't find that mushroom thing. All I saw was a fitting that looks like the ones you put grease into. Does anyone have a pic or diagram?

It's on the top side of the axle, off from one side of the pumpkin (differential assy). should be no grease fittings there... but, if the dust cover is MISSING, it may look like a large fitting. that would be a definite sign that you NEED one.

They are usually overlooked... but, they should be removed/ inspected/ replaced anytime a seal (pinion, thru, or wheel seal) is replaced.

[Bigmon]

It was getting dark out and I couldn't find that mushroom thing. All I saw was a fitting that looks like the ones you put grease into. Does anyone have a pic or diagram?

It's on the top side of the axle, off from one side of the pumpkin (differential assy). should be no grease fittings there... but, if the dust cover is MISSING, it may look like a large fitting. that would be a definite sign that you NEED one.

They are usually overlooked... but, they should be removed/ inspected/ replaced anytime a seal (pinion, thru, or wheel seal) is replaced.

The only thing I see looks like grease fittings. I'll take a look again. I cleaned off the fluid that was leaking and hasn't leaked for 3 days. It might have been residual left over from before, but I'll keep an eye on it.