Brake pad replacement now overheating rr brake

[joeplazek]

I replaced the brake pads on the rear of my 1996 Monaco Signature this spring. I have done this job before so that's why I am stumped. I went for a top off in fuel last week and i could smell hot brakes coming from the rear at the fuel stop. When I got back to the shop I crawled under it and found the right rear brake rotor hot (500 degrees) vs the left rear at 200 degrees. I thought i had not adjusted the slack adjuster properly so I readjusted. All seemed good. Went for another test drive and the right rear was hot again. Pulled the right rear wheels off and checked everything again. Checked for hang up by rotating the hub (axle out) and applying the service brake (with parking brake off of course). All seems to check out well. What am I missing? Left rear is adjusted the same and not overheating. We are puzzled.

joe

[MrMark52]

Originally Posted by joeplazek

I replaced the brake pads on the rear of my 1996 Monaco Signature this spring. I have done this job before so that's why I am stumped. I went for a top off in fuel last week and i could smell hot brakes coming from the rear at the fuel stop. When I got back to the shop I crawled under it and found the right rear brake rotor hot (500 degrees) vs the left rear at 200 degrees. I thought i had not adjusted the slack adjuster properly so I readjusted. All seemed good. Went for another test drive and the right rear was hot again. Pulled the right rear wheels off and checked everything again. Checked for hang up by rotating the hub (axle out) and applying the service brake (with parking brake off of course). All seems to check out well. What am I missing? Left rear is adjusted the same and not overheating. We are puzzled.

joe

First off - whose chassis?

2nd - am assuming this is drum brakes - have you compared that the left and right drum spring assemblies are identical?

3rd - when was the last time you bled the hydraulic system and/or replace the brake hydraulic lines?
Brake lines have been known to fail internally and act as a slow bleed check valve. It’s coincidental that it happened when you put new shoes on, but if there was much sludge in the hydraulic system because it hasn’t been properly maintained, a chunk of sludge may have dislodged and is causing the check valve affect mentioned above.

In over 50 years of working on cars, I had never run into the problem of the hoses until recently. On our ‘03 Jeep when we bought her 3 years ago, and my daughters ‘01 VW back in ‘06.

[joeplazek]

Originally Posted by MrMark52

First off - whose chassis?

2nd - am assuming this is drum brakes - have you compared that the left and right drum spring assemblies are identical?

3rd - when was the last time you bled the hydraulic system and/or replace the brake hydraulic lines?
Brake lines have been known to fail internally and act as a slow bleed check valve. It’s coincidental that it happened when you put new shoes on, but if there was much sludge in the hydraulic system because it hasn’t been properly maintained, a chunk of sludge may have dislodged and is causing the check valve affect mentioned above.

In over 50 years of working on cars, I had never run into the problem of the hoses until recently. On our ‘03 Jeep when we bought her 3 years ago, and my daughters ‘01 VW back in ‘06.

Roadmaster chassis. Meritor air disc brake set up. Disc’s front and rear. Sorry for not putting that in the post.

Joe

[MrMark52]

Rut - roh!

To my previous post - Nevermind. ��

[wolfe10]

Did you lube the grease zirk on the brakes? If so, did you go through the proper bleed process? If not, they will not release properly.


Were slide pins clean and not pitted?

[jacwjames]

What does the rotor look like, any chance it is warped?

Did you disassemble the calipers and clean the pistons, could they be hanging up.
Can you tell if they are releasing correctly.



Not gonna lie, don't have disc brakes on my rig but these are the two things I'd look for if I were having trouble with one of my vehicles. The last time I had a problem with my wives Chrysler van it turned out to be the line going to the caliper, it had collapsed on the inside and wouldn't let the pressure release.

[joeplazek]

Originally Posted by jacwjames

What does the rotor look like, any chance it is warped?

Did you disassemble the calipers and clean the pistons, could they be hanging up.
Can you tell if they are releasing correctly.



Not gonna lie, don't have disc brakes on my rig but these are the two things I'd look for if I were having trouble with one of my vehicles. The last time I had a problem with my wives Chrysler van it turned out to be the line going to the caliper, it had collapsed on the inside and wouldn't let the pressure release.

We have considered a warped rotor. Going to check that out more thoroughly. We are releasing them by the Meritor manual. They are well lubed as I have a auto greaser on the chassis. I dont know if air brakes would have a hose problem. It is exhausting fine. We have checked for drag by hand after applying them.

joe

[joeplazek]

Originally Posted by wolfe10

Did you lube the grease zirk on the brakes? If so, did you go through the proper bleed process? If not, they will not release properly.


Were slide pins clean and not pitted?

Auto greaser and air brakes. Slides are cleaned and greased.

joe

[wolfe10]

Originally Posted by joeplazek

Auto greaser and air brakes.

joe

Sorry, not sure I understand.


Proper grease/bleed procedure is on pages 114 and 115 of this Meritor publication:


http://graphicvillage.org/meritor/MM1.pdf


And Meritor recommends against grease on slide pins, as it will attract dirt and can cause lazy side to not release.


Lastly, Meritor has spring kits that help the lazy side release-- a very good idea.

[joeplazek]

Originally Posted by wolfe10

Sorry, not sure I understand.


Proper grease/bleed procedure is on pages 114 and 115 of this Meritor publication:


http://graphicvillage.org/meritor/MM1.pdf


And Meritor recommends against grease on slide pins, as it will attract dirt and can cause lazy side to not release.


Lastly, Meritor has spring kits that help the lazy side release-- a very good idea.

Sorry the auto greaser is connected directly to the caliper. I don't use a bunch of grease on the sliders but I did lightly coat them with brake grease (high temp). They are nice and free. That spring kit would be a good idea. The calipers can be moved by hand. I have watched the Meritor U Tube and all seems fine there. The more I look into it the more puzzled I become.

joe

[wolfe10]

Yes, if the lazy side is not retracting as it should and pins are clean and grease properly bled, absolutely, install the Meritor helper springs. They are specifically designed to make sure the lazy side retracts as it should.

[Pillbox]

Check your s cam…..

[joeplazek]

Originally Posted by Pillbox

Check your s cam…..

No S cam

Meritor Disc Brake set up.

[joeplazek]

Anyone?? Help?


joe