2nd Gen Non-Engine/Transmission FAST brake pad wear, Caliper not releasing?

[icarus33]

I ran down a set of Carbon Met. pads within 15k miles. Replaced with same and did a caliper rebuild with the o-ring and dust boot, new slide pin boots and silicon grease.

I continue to have considerable brake dust on the right wheel, where the pad wear was the worst. During last weeks tire rotation, I used a fishing scale to measure the force needed to rurn the hub/rotor with the wheels off.

Right side was 33lbs, Left side 18lbs. Took the calipers off the mount to measure just the axle/rotor/bearing assy. Right was 5lbs, left almost 3lbs. So the freewheel of the axles are about the same. It appears that the right caliper continues to be a problem. I don't have any brake pull however.

The fluid lines tee off near the frame on the left side to each wheel so I would not expect the right side to be sitting with a higher static pressure when the brake pedal is released. Kind of eliminates an issue with the master cylinder/booster.

Other than replacing the calipers, anyone see anything I'm missing or could try. What flavor of rebuilt calipers has the list had success with? Rebuilds from American Reman. were suggested by Peterson.



ic

 

[DiTrani]

BTDT

I spent a lot of time and $$ with the exact same problem on a Subaru. The cylinder(s) and piston(s) need to be honed and polished, respectively. Unless you have experience at this I'd recommend replacing the caliper, since you can spend a lot of time and either not fix the problem or remove too much material and have a leaky caliper.

 

[illflem]

If you remove your calipers you'll notice the slide surfaces look like they were forged in Afghanistan. Smooth them out with a flat file. Don't get carried away, it won't take much.

 

[jtadysak]

I had the same problem on another vehicle... rebuilt caliper. . replaced caliper 2 times. . one autozone and one napa. . replaced master cylinder. . replaced rotors. . I was stumped. so I replaced the last thing on the system that had'nt been replace... the brake hoses... and low and behold the problem disappeared. . the car had 70,000 miles on it and was a 93...

 

[illflem]

Sometimes a hose will delaminate inside and the loose part will act like a check (one way) valve not allowing the caliper to retract. The way to eliminate that possibility is to release some pressure with the bleed screw then measure with your fish scale to see if it makes a difference.

 

[icarus33]

This last brake rebuild was major. Like I had told Sam, I had wire brushed, sanded the calipers and knuckle slide surfaces clean enough to eat off of. I had the horrific brake squeal as well. Caliper pistons were in excellent shape when taken apart during the rebuild. Installed Brembo rotors from Tirerack also during that teardown due to a bad warp.

I have read about the rubber lines getting soft and causing a "mushy" pedal feel, hadn't thought about the innards getting so bad as to hold fluid pressure. I'll give that bleed screw relief test a try too before springing for calipers.



Thanks,



ic