Stuck Brake

[Adam Hicklin]

It appears I have a stuck brake on the passenger side rear. Luckily, only drove about 1/2 a mile. Smells of brake and is hot. Seemed to be driving ok but now that I think about it, something did seem a little off. Help!  Is this something I can fix myself?  

[Marty and Suzie Schenck]

If you have the air over hydraulic disc brakes, the caliper slides need to be lubed OFTEN!!! The calipers can get lop-sided or cocked in the rails if the slide rails are not lubed. This will cause the brake lining on the pads to wear uneven and wear down to the metal. Marty

[Gerald Farris]

Adam,
Your 98 Marquis has air brakes and not the air over hydraulic that Marty is referring to. There are two different air brake systems that were used on the 98 Marquis. If your coach was one of the first 25 or so 98 Marquis coaches that were built, it has a Gillig chassis. But if it was built after that, it has a Magnum chassis. I will need to know what chassis you have before I can help you with the repair. It may only be something like the parking brake not releasing. However, if you are not familiar with air brake systems, you probably need to have someone who if qualified make the repair.

Gerald  

[Adam Hicklin]

Gerald, it is the Magnum chassis.

So, after I posted, I climbed under the coach. It defiantly was the right rear wheel. The park brake rotor was dirty and rusted so I assumed it was not the park break hanging up. I did some gentle tapping on the right rear caliper, thinking it was just rubbing the rotor.  It drove fine, the only reason I knew something was wrong was the smell, then the heat when I went back to investigate the smell. After my tapping, I started it up. I was on a slight hill so I released the park break, pumped the breaks a few times then let it roll forward about 10 feet in neutral. Didn't feel any resistance. Drove about a 100 yards, got out and checked. No heat, no smell. Drove about 1/4 mile. Checked. No heat, no smell. Drove a couple miles. Checked. No heat, no smell. Everything seemed fine. Drove 250 miles without incident.

This was the first time the coach had moved in a couple months so I'm chalking it up to a sticky caliper. But I am interested in the process of maintaining these brakes. Gerald, do these calipers need to be lubricated periodically?  

Any help is appreciated.

[Gerald Farris]

Adam,
The parking brake rotor that you referred to is not used on your coach. The parking brake on your coach is incorporated into the rear wheel brakes.

There are specific lubrication requirements for the Meritor ADB brakes on your coach. One of the worst things that you can do to the brakes on your coach is to let someone lubricate the brake calipers with regular chassis grease when they are lubricating the chassis. The ADB brakes require lubrication with a very high temperature clay based grease, using a specific procedure. You can download the maintenance manual for your brakes from the Meritor website, or I will email you a copy.

You need to be careful with the maintenance on your brakes, because improper maintenance can and will cause a very early and expensive failure. If you have any questions after you read the maintenance manual, call me, I can walk you through any repairs.

Gerald    

[Edward Buker]

Gerald,

I'm a little confused on this slide pin lube maintenance some refer to. On the Meritor ADB brakes I have stuck with the Meritor Clay based grease and followed the procedure removing the excess to allow for expansion of the grease. When it comes to the slide pins, they have bushings that are to be gauged and replaced when wear becomes an issue. To date I have not lubed any slide pins on this particular brake configuration and I do not think the manual has a procedure and a frequency to lube the pins as part of maintenance. I know if you change pads and have them apart you would want to clean the pins and check the bushings for wear. What have you been doing regarding the slide pins on your Meritors?

Later Ed

[Gerald Farris]

Ed,
The Meritor ADB slide pins are chrome plated, and the calipers have bushings that they ride in, therefore rust and corrosion are not normally an issue. Cleaning and inspecting the caliper pins and bushings when replacing the pads is normally all that is necessary.

Gerald  

[Edward Buker]

Thanks Gerald, as always your wisdom is much appreciated.

Later Ed

[Adam Hicklin]

Thanks Gerald. I'll download the manual and take a look.  The last thing I want or need is an expensive failure.  Thanks for the advice and offer.  You may just be getting a call.

[Marty and Suzie Schenck]

Ed, in the manual I have for our disc brakes it states: do not lube or use anti-seize compound on the chrome pins or bushings. Just put them together dry. Measure tolerances and replace pins and bushings as necessary. Marty

[Edward Buker]

Thanks Marty. I was verifying what I thought I remembered....you know how that goes some days :-)

Later Ed

[Adam Hicklin]

Gerald, can the brake lune be done without removing the wheels?

[Gerald Farris]

Adam,
When you say brake lune, I assume you are talking about lubricating your brake calipers. If so the answer is yes, but there is a specific procedure that must be followed when lubricating your Meritor brake calipers, so do not lubricate them until you have a thorough knowledge of the procedure. However, if you want to remove, clean, and check the caliper pins or change brake pads, wheel removal will be necessary.

Gerald
    

[Adam Hicklin]

I guess my real question was is it just a matter of finding the zerk fitting with the wheels on, and injecting the correct grease, or if it was more involved.  Sounds like its more involved so I will have it done.  Don't want to screw things up that can kill me.  

[Gerald Farris]

Adam,
It is more involved than just pumping in grease, therefore I would not have someone service your brakes unless they were knowledgeable of the specific service requirements of the Meritor ADB system. The average "RV technician" will probable do more damage than good.

Gerald