94 Disco... Just over 145K.

The driver's side front caliper siezed about 2 years ago. Replaced it back then. New pads all around about 9 months ago. About a month ago the front brake pads were almost gone? Replaced the pads again. Today my son calls me and says the front driver's breake was smoking. Looks like the new caliper started to seize or got stuck closed for a while. It is not siezed.

Any ideas if the ABS Pressure Reducing Valve can go bad and keep one brake going? Can the ABS Pump do this too?

No clue how to troubleshoot this one.


Joe

 

How are your brake lines and hoses looking?

 

Not sure about eventual solution - but one troubleshooting trick is to use an infrared thermometer to "shoot" the brake disc on each wheel. Ones on the same axle should be about the same temp. That may tell you good / bad before you drive it enough for smokin' results. As just part of the next repair step would suggest that brake fluid flush could be in order as well, to remove contamination that might be reaching the calipers.

You should be able to drive the vehicle with ABS disconected, which should produce codes and warning lights. You won't have modulated brakes, but the regular function should still work.

I had a dragging caliper which was also the root of a warped rotor, combined with wheel bearings as part of the "Death Wobble".

 

Noticed the brake fluid is a dark grey color. Not the nice almost clear honey color it should be. Have been planning to flush it out with new GTLMA. Will do so.

Brake lines all look good. No leaks or buldges. Ditto with the ABS Motor. Pulling that out of the circuit via the fuse would work as a test?

Now... is there a way to troubleshoot the ABS Pressure Reducing Valve?


BTW... I have a Mighty Mike vac which I used to bleed the lines prior. Works but can be a pain to use... neeed someone to pump the pedal.

Anyone use the Brake Bleeder Tool from AB that uses shop air (AB Item: SDW7010)?

Have seen others that do not vac but attach to the top of the MC Reservoir and pos pressureize the system. AB has one (Item: 9508) but it says for pre-ABS systems only? Maybe adding pos pressure is a non-no to ABS here?

Joe

 

I was told that calipers as well as bearings should be done o9n a per axle basis, that is replace both not one individually.

The brake fluid being dark is the contamination in the fluid. I have used a turkey baster to suck out the old brake fluid as part of a flushing operation. Continue to bleed at the calipers until you get clear new brake fluid coming out.