Checking under the front end of a MCI 9

johns4104s · February 28, 2009, 04:30:31 PM

On checking the front end I see,

1) Oil on the bottom of the left lower break shoe, the leak is the oil is only on the bottom shoe, may be a leaking seal?

2) Looking front to back two large tanks, are they air? The tank on the right has a very large tube coming from above and right angling into the tank. This fitting is leaking a small amount of oil.

What do you guys think

John

Tom Y · February 28, 2009, 05:34:54 PM

John, have you ever empted those tanks? It sounds like you need to. Oil from compressor has built up. Tom Y

buswarrior · February 28, 2009, 10:11:01 PM

Oil on the brakes is bad.

If one seal is leaking, plan to change the rest, they won't be far behind.

You want to pull the hubs for brake inspection anyway...

happy coaching!
buswarrior

johns4104s · March 01, 2009, 05:15:51 AM

Tom/Buswarrior

No I have not drained the tanks, I will. I there a drain for each tank?

The brake shoes look nice and thick ( I will measure them) so having oil on them do they need replacing??

John

JackConrad · March 01, 2009, 08:03:42 AM

Quote from: johns4104s on March 01, 2009, 05:15:51 AM

No I have not drained the tanks, I will. I there a drain for each tank?
John

There should be a drain on each tank. We relaced the drains on our coach with ones that have a lanyard you pull to drain the tank. We have the lanyards inside the fuel fill door. Jack

Jriddle · March 01, 2009, 08:27:35 AM

I have always got rid of brakes that have gotten oil on them. They tend to grab and lock up that wheel. At 60 mph that is not a good thing I would buy new shoes

John

buswarrior · March 01, 2009, 08:46:17 AM

There have been raging debates regarding replacing oil/grease soaked brake linings.

With the prime motive costs, not safety.

If you can find an engineer that works in brake materials to recommend you keep them, go for it.

happy coaching!
buswarrior

Tom Y · March 01, 2009, 09:34:31 AM

John, I looked under my 5c. The drains are not on the bottom. I got oil out of one tank, I think the drains are up the side a little but pick up off the bottom. I did not climb under to be sure. If you need me to I will, let me know. Tom Y

NJT 5573 · March 01, 2009, 11:11:41 AM

Keep in mind if you drain the air tanks the suspension will drop and you can get killed.

Changing a set of brake shoes can open a lot of issues. The old shoes are seated to the drum, how are you going to seat a new set? If you don't do it right , they won't work right for many many miles or until they wear in and seat on their own. On the west coast with a loaded truck that can be a few 5 mile grades and a couple of adjustments, but a bus has alot more brake capacity than a loaded truck and it would take forever, and you would not have dependable brakes until they seated. I have never smoked the brakes in 15 years of owning a bus and I can smoke the brakes on a loaded truck anyday around here.

I can't believe that oil, gas or even air can penetrate todays brake shoes. I bet the same people who want to throw away the shoes because they have oil on them also would want to throw away the drums. The people who want to throw the shoes always want to sell you some more. The real issue of throwing away the shoes is how to clean them. I have cleaned them with gasoline and also poured gas on them and set them on fire. Gas is dangerous and perhaps that is a very good reason not to reuse a shoe set, but not a good enough reason for me. If I relied on an engineer to keep my little fleet running, I would have been broke before I started 40 years ago.

zubzub · March 01, 2009, 01:21:12 PM

uh oh here we go again

gm4106 · March 01, 2009, 02:42:13 PM

NJT 5572 is right. I started out changing two rear wheel studs. Before I took my drum off my liners look to be 90%. But what a joke on me after removing the drums. My drums where way out of speck, deep groves in the drums, liners felt like a ocean all wavey and slack adjusters bushing where shout. I needed to replace a S cam. After all that $1500.00 for two wheel studs. At that time I went and drained all the tanks the main tank had about 2 quarts of water and 4 gallons of oil. That's right I couldn't believe my eyes. But today everythings is right and I feel safe and happy.

pvcces · March 01, 2009, 10:13:08 PM

Draining the air tanks should have no effect on the suspension; when it does, the leaks need to be fixed.

I agree; if the suspension does settle, it could ruin your whole day.

Tom Caffrey

johns4104s · March 02, 2009, 03:47:35 AM

Now I have my pit I feel a lot safer. However that front air level gauge is easily knocked. I will block the body independent.

John

NewbeeMC9 · March 03, 2009, 10:39:10 AM

John4104

You should have drain valves with little spring loaded toggles on the end of them and lanyards going out to a convenient place. My lanyards come out at the wheel wells.

You should drain them daily in use, I try to drain mine whenever I get somewhere right after I shut it down.

Sojourner · March 03, 2009, 01:29:29 PM

About oily or greasy brake lining: You can replace them (R&R) by having the drum turned if it within DOT specification limit and shoes to match it to a new diameter or new drum. Or you can just clean them like many fleet garages do. I had work at 2 difference fleet garages that came in with oil soak lining and oil coated on the inward side of the tire wall. The result after a good thorough cleaning...it continues to do braking with many more miles like it never happen before.
1)   To clean the oil or grease off of lining is to use a stiff parts brush to wash it with white spirit, also known as Stoddard solvent is a petroleum-based solvent. You can use flammable gasoline or kerosene but do it out door due to the dangerous vapor. Or low-pressure (about 1100 or less psi) wash.
2)   The next important step is to remove the petroleum-based solvent off to avoid glazing to cause the squealing. Soaked a clean shop rag with acetone (flammable) to wipe over the lining until it is very dry & cleaned surface. In other words if the second going over with a soaked shop rag come clean fairly well...it done.
3)   If there any glaze on lining's surface. Deglaze it with 80 grit sand paper well until the shine is removed.
4)   Deglaze unturned drum's surface using same paper until a lot of hair-line scratches on the fiction's surface. This help to break-in quicker for better stopping power.

Ether or Acetone is organic compound will leave no oil residue

All brake lining come factory equips with oil & resin within the compound to hold it in shape or it will be cracked in many places or fall off the shoe's backing. Over heated braking can and will dry up the lining. Been there to report this.

Sojourn for Christ, Gerald