replacing wheel bearing and seal

David Anderson · March 05, 2019, 02:23:43 PM

I noticed a bit of oil on my bogie hub and pulled the plug and it was a bit low. I crawled under the coach and the inner seal is failing and it slung a bit of oil on the brake drum. How hard is this to remove and change? Do I have to remove the brake assembly? Is my drum and brake shoes ruined? I have the manual with pictures attached below.

It would be wise to replace the bearings, race and seals while this thing is apart.
Where would I get the parts??

David

David Anderson · March 05, 2019, 02:25:10 PM

Here are the diagrams of the brake assembly

chessie4905 · March 05, 2019, 02:37:48 PM

You can remove drum and hub and clean drum with a parts cleaning brush and solvent. The shoes can be left in place and cleaned with shoes in place. Clean thoroughly, paying particular attention to the rivet/ bolt holes. I've used a small flat head screwdriver with a rag to remove any the brush missed. Do springs and other hardware also. A can or two of aerosol brake clean after finish with the solvent helps with missed or inexcessible areas. On ours, after done, I heated the brake surface some to sweat remaining oil out of the lining. Did it two or three times and wiped residue off after each heating. Dont go crazy with the heat two or three bundred degrees at most.

TomC · March 05, 2019, 03:17:55 PM

With the relatively cheap cost of relining the brakes, I wouldn't goof with trying to clean oil soaked brakes. I would replace both sides with new. If one side is leaking, you can bet the other side is close to ready also. Good Luck, TomC

chessie4905 · March 05, 2019, 03:23:37 PM

Yes you can, but what if you bugger the seal the first time or the hub seal surface is bad. Do you replace the lining each time? It also depends on how worn or cracked the lining and drum or drums are. His call.

luvrbus · March 05, 2019, 06:49:56 PM

David the bearings and seal are off the shelf a truck supply or bearing supply will have those even Napa can order for you,if the lining is in good shape I use lacquer thinner and heat to clean the shoes with a light sanding to remove the glaze

David Anderson · March 05, 2019, 08:30:10 PM

Quote from: luvrbus on March 05, 2019, 06:49:56 PM
David the bearings and seal are off the shelf a truck supply or bearing supply will have those even Napa can order for you,if the lining is in good shape I use lacquer thinner and heat to clean the shoes with a light sanding to remove the glaze

Anyone have the part numbers for the bearings, bearing cone, and seal? I'll have to replace the hub cap seal, too.

Jim Eh. · March 06, 2019, 02:50:30 AM

The bearing numbers are stamped into the cup and cone. You can do a thorough inspection of the bearings before condemning them. A seal leak does not necessarily mean a bearing failure and those bearings are design and built to last. Post up pictures of the linings and drum when you get it apart. I am in the camp that if the lining is contaminated, just change it but that is just me.

chessie4905 · March 06, 2019, 04:05:38 AM

When you examine the bearings, clean thoroughly and shine a bright flashlight or equivalent so you can see the surface the rollers ride against in their cage. Sometimes rollers and bearings look good but roller surface has pits and bad surface, so check them close. They may make an equivalent to that seal that is designed to have the sealing surface inside itself in the seal instead of the normal hub seal surface. Scotseal used to offer this, although there are probably more now. Be sure to use flat piece of board or similiar or proper seal installer. It can be easy do damage new seal installing it if you don't have some experience doing it. Denting one side of seal installing it will surely cause leakage again.

David Anderson · March 25, 2019, 10:54:43 AM

Ok, I finally got the time to do this. I had a 300 mile trip I had to make and now have no more trips till May. Wow, I'm glad I found this because I filled the hub before the trip and when I removed the hub it only had about 4 oz of oil in it. The seal really failed.

Anyway it was really easy to get this apart. (Youtube has been my friend) I cleaned everything up and have 16.5" of wheel drum diameter, 16.8" is stamped on the drum so ok there. Very few hairlined cracks showing. I have 3/8" brake pad on the shoe. I am going to clean with lacquer thinner and see how much oil I wick out of the shoes and drum. I still need to get the inner bearing and races out, which I will attempt this afternoon. I was able to remove the locknuts with pliers, but will purchase a socket to reinstall. It requires 200lbs preload torque, then back off to hand tight only. I have a concern about the outer seal shroud mounted to the axle. It is not perfectly round, but has a dent or two on it. Not sure if you can see it in the picture, but zoom into picture #11 and you may be able to see it. I can probably straighten it all out, but not sure how it got the dings in it. It may not matter. It looks mainly like a dust shield for the oil seal.

Opinions and ideas are welcome

David

David Anderson · March 25, 2019, 10:55:31 AM

more pics

David Anderson · March 25, 2019, 10:56:19 AM

more after some cleaning

buswarrior · March 25, 2019, 11:02:56 AM

Brake lining is porous, like a sponge.

The amount of oil that has soaked into the lining is the concern. It migrates back out during brake use, reducing the friction at that wheel end.

Tough decision, depending on whether it got a splash or was soaked...

Soaked? Definitely change them.

Less than that? Tough call...

Happy coaching!
Buswarrior

Jim Eh. · March 25, 2019, 04:18:13 PM

My thoughts, FWIW, the wheel and drum are already off, the cost of a replacement set of brake shoes is not going to break the bank.
The amount of brake cam travel on the rollers is also a bit of a worry. How much did you back the brakes off to pull the wheel? The combination of worn linings and a worn brake drum could lead to a condition known as "over-camming". That's when the brake cam S head rotates past the rollers on the brake shoes. Kinda hard to tell from pictures but ...
When that happens, at a minimum, you lose all braking in that wheel. At worst, loose parts roll around and pile up.

If you are to replace the seal and brake shoes properly now, it is unlikely you will ever have to pull that wheel for servicing during your ownership of that bus.

chessie4905 · March 25, 2019, 04:25:43 PM

I've heated the lining a few times with a propane torch. It causes the lining to sweat out the grease.Then wipe and spray with lacquer thinner or brake clean. Repeat a couple of times. Bearings packed with synthetic grease don't leak all over the lining and drum like the oil does. Just sayin...