Air Disc Brakes by Rockwell Meritor

[Pat Long]

I have been reading a lot about disc brake problems on here and have also had some issues also.  After watching the Rockwell Meritor video several times to figure out my problem I though I would share what I have been experiencing with my situation.  According to the video you should only grease the caliper twice in the lifetime of the brakes and after lubing the caliper you have to expel the air and extra grease you just added so as to allow the caliper to return to the Neutral position so the pads will not drag on the rotor itself.  Too much grease or an air pocket will affect the return to Neutral Position.  I had two that were dragging and one that required the replacement of the pads because of this very situation, so I replaced both sets on that very axle. 

So the next time you lube expel the air and extra grease, and readjust the brakes.  And yes I have installed the Rockwell return spring update on ALL the caliper slide pins, KIT15018 for those who don't have that info.

[Gerald Farris]

Pat,
There is another issue that can cause a dragging brake on the Meritor ADB brake system, and that is the condition of the slide pins. The slide pins are chrome plated, hardened steel, and if the chrome plating wears through it can catch on the caliper causing a dragging brake. Since all of these coaches are pushing the 20 year make, the caliper pins should be checked any time they are removed.

If you have Meritor ADB brakes (Magnum chassis 1998 to 2002 Marquis, 2002 Thunder, and all Solitaires) the lubrication method that Pat is referring to is completely explained, starting on page 52 in the service and repair manual located here; http://www.meritorwabco.com/meritorwabco_document/mm4m.pdf

Gerald 

[Pat Long]

Gerald,   My slide pins and All In Very Good Condition.  Inspected them before I installed the update return springs.  I am now in the process of replacing the 18 year old maxi cans and have to find the correct replacement.  The old ones have a hard time returning after application.  Checked everything after install of the new disc pads last week.   Had a friend of mine apply the brakes while I was under the coach after install to inspect applied travel after I mad the adjustments to the brakes.  Thats when I saw that the cans were having a hard time releasing after application.