Massive gook buildup on brake drum

[Buffalo SpaceShip]

I went out to adjust the brakes this afternoon for our trip home from Dallas to Denver on Sunday. To my dismay, the pax. rear drum looks like this (tp pic)... pushrod is also wet (bottom pic)...

Over-zealous lube job (before I bought it)? Some type of failure? Any ideas??

Thanks,
Brian

[FloridaCliff]

Brian,

That looks like the goop came out of my air tanks the first couple of times I drained them.

Hard to tell from the photo's how it got there, unless it blew out from a unseen location.

Seal on the DD3 by the push rod?

Cliff

[Ncbob]

Hate to disagree, Cliff...m'friend, but how in the world could 'goop' from the actuator get past the actuator rod, past the slack adjuster, through the "S' Cam shaft and into the brake drum?

I believe that overzealous applications of grease through any of the fittings, EG.  Brake anchor pins, "S" cam shafts might be the source of the problem.

Solution: IMHO

Remove the wheels, hubs and drums and clean that mess up.  It's certainly not safe.

FWIW

NCbob

[buswarrior]

And, you really should get a fresh brake lining.

Linings are porous and soak up lube.

And the brake won't do its friction job properly.

From the pics, I don't see enough splatter to suggest the lube came from the axle. You running grease or oil?  If grease, look carefully for evidence of axle seal failure that the pics aren't showing us.

crumbs, this is a pain, I feel for you!

happy coaching!
buswarrior

[FloridaCliff]

Bob,

No offense taken.  

I was just offering OTHER possibilities since Brian had ALREADY mentioned the possible grease ovefill.  

Cliff

[Abajaba]

It would appear to be more likely that an axle seal is bad here.  There appears to be too much gook and such on there to be from a couple of extra grease gun squirts.  I would postulate that the stuff is a combination of warn brake material and axle lube.

Would you please let us know what is being used for axle lube here?  Is it grease or oil?

The suggestion to fix the problem and change the brake linings is a good one.  If they are as badly contaminated as this one looks, it is not safe.

                                                Abajaba

[TomC]

Swipe some of that greasy stuff and smell it.  If it doesn't have much smell, it is grease.  If it has a burny, strong smell, it is axle oil.  I don't know of any drive axles that use grease in it.  Either someone squeezed in too much grease, or more likely you have a blown wheel seal.  It doesn't take much oil to make a big mess.  Whatever it is, you need to get it repaired and install new linings (would be best to have both sides done to keep things balanced)  Good Luck, TomC

[Ncbob]

Right, Cliff, but now that I review the pic I can see why Ewan is taking a look at the axle seals too.  That's another probelm we have a tendancy to overlook on these old buses.  I replaced not only my rear shoes, actuators but the seals as well this year. 

And for the milage I'll be putting on that old girl...she ought to be good for another 40 years.

And be ready for some serious brake shoe replacements prices...mine cost me $94.00 each (that's X 4)!  But then, I live in Podunk, USA, where items like these aren't readily available.

[gumpy]

Looks like wheel seal failure to me. Oil mixed with brake dust and dirt.

Time for a brake job. That one isn't doing you much good.

[Busted Knuckle]

Brian for now go to the parts store and pick up about 4 cans of Brake Parts cleaner and heavily soak everything in that hub EVERYWHERE you can spray it with the first 2 cans (might wanna get one of those cheap "painters masks" to use while doing this! TRUST ME!) and spray fast and soaking, then crawl out from under there and let soak awhile 30 mins. to an hour. Then put the mask back on and go back under and quickly respray the 3rd can and retreat again letting soak again! Then just before you are ready to hit the road use the last can to soak it again, give it 10 mins. and hit the road, this should have you pretty well cleaned and get ya home!
When ya get home pull the brake drum and inspect and let us know how things look from there! I'll bet you'll find things in good shape. Let us know! BK  

[LUKE at US COACH]

Hi Brian & Folks;

Looking at your first photo, I do not see a bunch of grease/oil in an area other than the brake lining.  In a subsequent photos, it appears that the cam seal is weeping grease or oil.

Is this on just one wheel or one both???

I would agree with one previous message, that it would appear that the brake lining is grease or oil soaked, and in my shop it would have to be replaced.  Over the years I have seen too many folks try to save grease/oil soaked lining to no avail.  If a leak is caught just as it happens, perhaps the lining can be saved, however if this has been going on for a while, then it is best to cut the drum, replace the lining and know that you and your family are SAFE!!!

Whether you make your trip or not is your call, but the problem should be tended to eaither before or after your trip.

I Hope this HELPS!!!

Happy & SAFE!!! Bussin' to ALL.

LUKE at US COACH

[Buffalo SpaceShip]

I'd love to follow BK's advice, as long as it doesn't lead to some sort of failure on the road. I'm not exactly in a place to make major repairs or wait for parts to come in. I fruitlessly called around all day to try to find a set of front shocks... but settled to have a pair shipped home to arrive when I return next Monday. I'd love to do the same with the rear axle work... whatever it involves. But I don't want to put my family (or coach health) in harm's way.

I honestly don't know if my axles are grease or oil.  My manual' got left at home due to my haste and stupidity (it was on the LIST!)  , so I'm really shooting blind here. And I've never done the sort of work to know exactly how things work back there, other than adjust the brakes.

I did just crawl under and check the rear tank for oil. There's not much escaping. Same on the wet and dry tank, but there has been an unusual amount of wet oil coming out of the moisture ejector valve since leaving St. Louis. I just put some alcohol in the can when leaving Iowa as the weather was turning cold. I would think that would help soak up the water, not create more.  I have been putting off a compressor replace or re-build until after this trip. Is there any way that it's compressor gook blow-by (as Cliff originally suggested)?? There's been a decent amount of gook that comes out of the compressor tube thingy (what the heck is that called) ever since I bought her.

I also noticed that the axle breather had some same gook on it, and the DD3 vent had some caked-on oily crud. I wiped a whole bunch of that crap off of the brake cam. And LUKE (The God of the Bus Parts world responds to my post!  ), the issue is only on the pax. rear wheel... for now.

Ack, I'm freaking out here in the Big D!!

Brian B.

[buswarrior]

Hello Brian.

Never mind the compressor for now. It isn't that.
There isn't a source of lube in the DD3 or the other brake linkage components to further contribute to this, so forget them for now.

Here are your issues:

Brake performance
Bearing lubrication
Attracting unwanted attention from the authorities.

The last one only happens if it is visible from outside, or if you are leaving a trail to follow, or if you are acting strange and fooling around out where they can see you and get curious, if you know what I mean.

The first, you still have two good fronts and a good rear, ensure they are adjusted correctly.

The second, you need to be able to eye ball that mess and decide if the bearing cavity still has some lube left so the bearing will roll you home without a lube related failure.

Unfortunately, you are the only one that can decide whether you want to drive it home.

happy coaching!
buswarrior

[Paso One]

Hi Brian
First I would do what Tomc  said and smell it that should tell you what it is. Second I would do what Bryce said.  WAG that didn't happen on this trip and it's  Likly a axle seal that leaked on the shoes like that many miles ago.

I also noticed you have never complained about stopping power.

Sorry Luke  Your answer is correct and I wouldn't expect anything else But bryces suggestion will get you home .

[Stan]

I have a question for the GM experts. Does Brian's bus have grease packed rear axle bearings or do they lube from the differential?