Calipers

rwolffe

2 years ago, I did a brake job on the front of my 98 GC. I replaced a left front caliper, (it was seized), as well as pads, rotors and flex lines for both sides. 3 months later, I wound up having to replace the right front caliper (seized up). 3 months later, I had to replace the left front caliper again. It seized up. 4 months later, the right front caliper seized up. 3 months later, the right front caliper seized up again. 5 months later the right front caliper seized up again. 5 months later the right front caliper seized up again. That was 3 weeks ago. Last night, on my way home, when I pushed the brake pedal, it barely moved but the brakes worked better than ever. By the time I got home the caliper was seized up tight....again. I have tried different parts stores with different suppliers, new, rebuilt, you name it but this problem is persistent. I have even picked 2 of the calipers up from stores in Port Huron, Michigan, (I live in Ontario). Brake fluid here is very expensive ( I have spent in excess of $100 on brake fluid) and it takes me a couple of hours to replace the caliper. I remove the old one to take with me to get around the casting charge so it does take a little longer. I did a pressure test on the brakes to be sure it wasn't the flex line but everything was OK. I also replaced the proportional valves for the back brakes when they started leaking last year, however, that has nothing to do with the problems with the front. I do get a grinding sound in the right rear brake when it has been raining out or wet but it goes away within a couple of blocks. Seems to be typical of brake shoes on Dodge and Plymouth mini vans from around this year. Rear shoes and drums are in excellent condition but I have noticed rust on the shoe linings when I have pulled them apart when they were damp. Cylinders work good and there are no leaks. My main concern is all of these calipers. I just can't wrap my head around all of this. I'm wondering if anyone else has run into this problem and if they found a fix for it.

Thanks

imidazol97

I wondered if it's something related to the calipers but not the calipers themselves. I remember my earlier leSabre required 0.015 in. clearance top and bottom between the metal ledges that keep the caliper from moving too far on the bolts that they slide on with a rubber bushing. So I looked for your problem.

Found some similar suggestions for clearing away the rust on the brackets that hold the calipers:

"There could only be a couple of causes for the brakes dragging. The first is pressure in the brake lines, either by the driver applying the brakes, the vehicle applying the brakes (ie traction control or ABS) or pressure not being released (blocked/damaged brake hose). The second is the brake pads "wedging" into place because of tight clearances made even tighter because of heat and rust/corrosion. The latter seemed to me to be the most likely cause. This is in part because I have seen tight pad clearances cause damage to pads before. I had a Hyundai Sonata that required (rear) pad replacement long before the other pads were worn because
one had wedged in a postion that damaged the pad. I solved this problem by filing the surfaces of the pad that contact the pad guides (you might call them the channels in which the pads slide) and by using brake lube on those sliding surfaces. (Being careful to keep the lube away from the braking surfaces). I never had that problem again.
"With that in mind I took the caliper off as well as the mounting bracket. After wire brushing and filing the bracket (there was a lot of rust and buildup) I began to file the sliding surfaces of the bracket. I noticed that in addition to the indented worn spots where the pad "backing" moved, there was actually a rise inward toward the disc. In other words as the pads moved closer to the
disc the clearance got tighter and with the heat expansion I could see how the tremendous force applied by the caliper could literally "wedge" the brakes up against the disc. I filed and lubed the right front brakes. I thought about doing both and my wife wondered why I didn't do both. Since I wasn't sure that that was the cause, I figured if it happened again and only the left brakes seized, I would have my answer. Sure enough, in another week or so it happened again. Only this time it wasn't as bad. I could still feel the dragging but it didn't seem as pronounced. I stopped several times on the way home so the brakes wouldn't start smoking again. When I did get home I got my water mister and sprayed the left wheel and disc. Just as before sizzling and steam. However, when the right wheel was sprayed,... nothing. This wheel wasn't any hotter than the rear wheels. Question answered. I have since wire-brushed and filed the left bracket and pad "backing" and lubed the sliding surfaces. I'm confident that the problem is solved.
Read more at "https://answers.yahoo.com/question/index?qid=20100814194703AAZXfm9

rwolffe

I'm extremely sorry it took so long to get a response back to you. I tried several times but the response wouldn't go through. I have solved the problem. The right front flex line was causing the problem. The store replaced it at no charge. I no sooner got this problem resolved when the left front caliper started to heat up. The store has offered me another free replacement for the flex line. Both lines were replaced about 2 years ago. Before I could get to the left front flex line, 2 lines running between the ABS unit and the proportional valves ruptured. 2 lines with 4 different connectors that I had to drive about 75 miles to get since they weren't available here where I live. I had to get 2 adapters for bubble flare. One in 10 mm and 1 in 12 mm and a 3/16 to 10 mm adapter and a 3/16 to 12 mm adapter. I finally got everything repaired. I replaced all lines to the back end of the vehicle. This has been a disaster from the get go but most everything has been done. Left front flex line has to be done yet. I included adjusting the back shoes up as well but the grinding sound is still there when it is damp or wet. I pulled the drums and the shoes were good with very little wear to the drums. Adjusters were sticky so I removed, cleaned and lubed them. Right now, the brakes work better on this car than they did when I got it. I'm going to replace the left front flex line on Tuesday. Hopefully that will end my brake troubles.

I thank you very much for your input on this problem. It made me really think about it and got me to where the problem really was.

RWolffe

imidazol97

rwolffe said:

I thank you very much for your input on this problem. It made me really think about it and got me to where the problem really was.

RWolffe

I'm glad to hear you got your problem straightened out, even though it seems like it's
been a rough path with all the lines corroded and bursting too. Good luck
on the finishing step.