Rear Axle Leak

Hi everyone :)

Last year I made my first posts on the forum about trying to fix the brakes on a homemade tractor my Grandfather built in the early '80s.

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I'm not someone who is very mechanically inclined, but with your help I managed to replace the wheel cylinders and get the brakes working again.

While they worked, they didn't work very well. For a summer project this year, I decided to go back into the drums see if the shoes also needed replacing. Once inside the drum, I discovered everything was coated with a small amount of oil.

Unfortunately, this is where my shallow expertise falters. I'm not sure what would be causing the leak. I have some photos of the axle, the hub, and the bearings. If anyone has any advice on what needs replacing/fixing, it would be much appreciated.

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You have what is called a full floating axle. It has a seal that keeps the grease in it. The third from last, and next to last pictures show this seal. The seal can be
removed with a big screw driver placed under it on one side and prying downward against the other. Simple and direct. The seal keeps differential oil from getting out
into the drums. It will have a number on it that is easily duplicated by Motion Industries, NAPA, or Kaman Bearing. The shoes can be de oiled if heated with a propane
torch till they barely start on fire. Heat the entire shoe on a cinder block or brick, (not concrete). Do not let them get and stay on fire. just drive the oil out of
them. (on a truck, they can get nasty hot, but your job is to heat till no more oil comes out). The beaarings should be just fine. They can be installed with chassis
grease forced between the rollers. (Don't mix them up, they work with their mate) the grease will keep them lubed till oil gets to them from the differential. Check
the level of 90 wt gear oil in tha differential. New seals can be tapped into place with a piece of very square woo that covers the seal so it drives straight in flush.
Adjust the bearing preload so that you can just feel a little resistance to turning the drum. Easy hand pressure. Whack the drum a good lick with a hammer on its
shoulder, then readjust the preload as above. The brakes should drag as much as the preload, Look up doing this on youtube. Jim
 
The oil came from either the leaking wheel cylinder, or the grease seal, or both.

While it's apart, replace the grease seals. And pull the cups back on the wheel cylinder, just to be sure they are dry, even though they are new.

The drums look good, just clean them up with brake cleaner. Once the shoes are soaked with oil or fluid, it is impossible to get it all out. Replacing the shoes is the only sure way to eliminate the problem.

However, being this is used so minimally, if you don't want to spend the money, or can't find shoes, "sometimes" you can clean them up with brake cleaner, coarse sand paper, and burying them in something absorbent, like floor sweep. This should get them functional, but probably not going to be perfect.
 
Thanks for the great advice! :)

I checked the wheel cylinder and everything was good there. I've gone ahead and pulled out the seal (it gave quite a fight!) I'll stop by a parts store tomorrow and see what they have in stock.

I'm also planning on replacing the shoes. Jim, I appreciate the advice on saving the old pair. If replacing the seals doesn't solve the issue, I'll use your technique to save the new ones if they get oiled. :lol:
 
SnowStorm34
First off it is good to see you acquired some jack stands.
After degreasing the contact area of the brake drum, if it looks glazed up you can run a piece of emery paper over it.
If real heavy then take the drums in and have them cleaned up on a brake lathe.
 
One more thing to make note of when you install the brake shoes.
Two of the four shoes likely will have a slightly longer piece of friction material on it than the other two.
The shoe with the shorter friction goes toward the front of the vehicle on both sides.
 
And one thing I would like to add to Jim's reply that I feel is important is prepping the seal running surface on the axle. So it is the first machined surface on the axle toward the backing plate side. I would get some 150 grit emery tape and polish it with that first and then finish up with 220 grit. Hopefully you can buy a short 3 foot strip at your local auto parts store. Use the emery tape in a shoeshining motion as shown in the attached video (it's for plumbing but is the same idea). Then when you are placing the hub back on give it a good smear of new grease 360 around. Hope I did not over simplify this to much. That is a nice unit by the way. I'm not sure if you got to see the pictures of my home built garden tractor I posted yesterday? Yours is a lot nicer finished then mine with sheet metal and all. Good luck!
Emery tape use
 
After a busy morning running of around to five parts stores (including NAPA) I've ended up empty handed. I also called Motion Industries. The lady who answered said she needed to reach out to her contacts and she'd call me right back. It has been over 8 hours and I'm still waiting. :(

Ah well, I'm sure I can track one down.

SnowStorm34
First off it is good to see you acquired some jack stands.
After degreasing the contact area of the brake drum, if it looks glazed up you can run a piece of emery paper over it.
If real heavy then take the drums in and have them cleaned up on a brake lathe.

One more thing to make note of when you install the brake shoes.
Two of the four shoes likely will have a slightly longer piece of friction material on it than the other two.
The shoe with the shorter friction goes toward the front of the vehicle on both sides.

I took your advice to heart and got a pair of jack stands. As someone who likes to play it safe, when you informed me of the danger of using cinder blocks I decided that I didn't want to learn this lesson the hard way.

Thank you for your additional tips here! :)

And one thing I would like to add to Jim's reply that I feel is important is prepping the seal running surface on the axle. So it is the first machined surface on the axle toward the backing plate side. I would get some 150 grit emery tape and polish it with that first and then finish up with 220 grit. Hopefully you can buy a short 3 foot strip at your local auto parts store. Use the emery tape in a shoeshining motion as shown in the attached video (it's for plumbing but is the same idea). Then when you are placing the hub back on give it a good smear of new grease 360 around. Hope I did not over simplify this to much. That is a nice unit by the way. I'm not sure if you got to see the pictures of my home built garden tractor I posted yesterday? Yours is a lot nicer finished then mine with sheet metal and all. Good luck!
Emery tape use
Thanks, I'll do just that! And yes, I saw your photos. :) That's quite a nice machine you've got.
 
Finding the seals at an auto supply might be a little out of their league.

If Motion can't find them, try an old school auto supply, one with real parts books, and an ol' man that knows how to use them! LOL

Or a supply that leans more toward trucks and heavy equipment. They might can identify the axle by sight.
 
Finding the seals at an auto supply might be a little out of their league.

If Motion can't find them, try an old school auto supply, one with real parts books, and an ol' man that knows how to use them! LOL

Or a supply that leans more toward trucks and heavy equipment. They might can identify the axle by sight.
Thanks :) Yes, after going to a couple places I certainly got that vibe that regular auto supply stores wouldn't be able to help me. I'll try Motion again tomorrow.
 
Hi everyone, my seal has arrived. :D I ended up getting it from a company called BDI Express.

I banged up the old seal a fair bit when removing it so I don't have a good reference for which side is supposed to go in first, facing the oil.

Here are two pictures of my new seal. I'm pretty sure the "code side" faces the oil, whereas the side that has a little gap between the lip and the metal would face the dry/brake side.

If anyone could confirm or correct me on this, I would much appreciate it.

"Code Side" with a lip right against the metal
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Open Side where you can peek at the spring

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Thanks very much!
 
Upon a closer look at the old seal and a chat with a knowledgeable neighbor, it turns out my initial thoughts were wrong. Now that I know which way it goes in, it should be clear sailing from here. :)

Thanks again to everyone for your kind and helpful advice!
 

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