Jeep Garage  - Jeep Forum banner
1 - 8 of 8 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter · #1 ·
Hello, I've read many posts on a similiar issue but none have resolved my problem. After my 99 WJ (with single piston Teves calipers) sat for nearly a year I decided to put it back on the road. Everything was working fine but I decided to service the front brakes, new pads, rotors, calipers and flexible lines (I have had this jeep since new and always done my own brake work, without issue). Once that was done the rear calipers starting dragging (both sides) and it burned up the seal on the drivers side rear caliper. So i put new calipers, pads, and flexible lines (including the center line) on both sides in the rear. The rear steel line from the ABS to the rear was replaced about 5 years ago. I looked at the caliper brackets and they appear to be fine, no visible grooves. The slide pins were dry but I lubed them up and they appear to be working adequately.

My question is, what would cause both sides to bind after replacing the fronts. The obvious answer seemed to be either the flexible hoses or the caliper brackets, but the hoses have been replaced and as I could not see any groves I cleaned up the brackets and re-used them. However, I am still getting the drag on both sides. Not enough to keep the jeep from rolling in neutral on even the slightest incline, but once it has done 5 miles of city driving they are supper hot, dragging pretty good when coasting, and likely will burn up if then taken out onto the highway.

I am now considering replacing the pins and caliper brackets next, but could it more likely be the ABS module or Master cylinder? or something else? I have not replaced the rear rotors, but they are above min spec.

Something I recently read.... one of the things I may having been doing wrong is when I push the piston back into the caliper I have not ever opened a bleeder, I just open the master cap and go slowly using a C-clamp. Could this have damaged something in the ABS module that is causing this problem?

thanks,
Alden
 

·
Premium Member
Joined
·
1,476 Posts
when a caliper is in a dragging condition, open the bleeder and see if it releases.. to double check whether it is a hydraulic or a mechanical problem..

Always a good idea to open the bleeder when pushing back the caliper.. I usually do a fluid flush as well after doing a brake job.. just to keep things clean inside..
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #3 ·
Thanks, I will try that. I did open the bleeder once while it was dragging to see if it would expel fluid. Some fluid did come out, enough to fill about an inch of the drain tube. If it was a hydraulic issue how much fluid do you think I would see come out? I did not have the wheel jacked up at that time to see if it released, but will try that out. I have bled the brake lines (several times).

Thx
 

·
Premium Member
Joined
·
1,476 Posts
won't take much fluid to release the caliper
 

·
The beast from Brazil
Joined
·
8,310 Posts
The ABS system has three channels, one for each front wheel and one for both rear wheels. So since both rear wheels are dragging, the problem could be related to the ABS hydraulic control unit, or the master cylinder. Maybe dirt has clogged the rear wheel ABS release valve. Also the master cylinder has a primary circuit (for the front wheels) and a secondary circuit (for the rear wheels). Dirt could also here cause clogging. Maybe reverse flushing could send the dirt towards the reservoir.
 
  • Like
Reactions: aestey

·
The beast from Brazil
Joined
·
8,310 Posts
I would use a low pressure from a squeeze bottle or so and put it on on of the rear bleed nipples. Its just to create a slow back flow towards the reservoir and hopefully take any particles with it. Keep an eye on the reservoir level, that it not overflows.
 
  • Like
Reactions: aestey

·
Registered
Joined
·
121 Posts
I had all 4 wheels lock up, in traffic, and the only way to get off the road was to nail the gas and smoke the brakes. Bummer.... Let it cool for a couple hours, then drove it home with no issues. Turned out the master cyl was causing the issue.
 
1 - 8 of 8 Posts
Top