Freaking brakes.... need some trouble shooting advice
 

2001 D2 130,000 miles

4th owner

Original problem- Drivers rear brake started dragging on the rotor.

Replaced the caliper
Bled the system 1x (RR, LR, RF, LF)
Drove and all 4 calipers were dragging now...heat and smell to confirm
Researched...
Drove and activated ABS module on gravel road
Bled system 2x after that
now the other three calipers I didn't replace are dragging.

Not sure what to do. I'm pretty sure all the air is out of the system. I went through a lot of fluid. 2 qts

Why would the three that were ok all the sudden start dragging but the one that was replaced is fine?

Could all the other calipers go bad at the same time?

Am I looking at more of a master cylinder issue?

Help is needed!

Did the systems bleed up well - did you get a good firm pedal.

One point if you are not 100% confident of checking your and diagnosing this problem take the Disco to a professional - bad brakes put you and all other drivers around you at risk.

As to master cylinder drag is not usually a problem, getting the brakes to activate is but go through this :

I took this from another site

Step 1

Open the hood of your car and locate the brake fluid reservoir. It will be towards the back of the engine bay and will be a plastic cylinder filled with hydraulic fluid. If you have a manual transmission car, there will be two of these; the brake fluid reservoir is the larger one.

Step 2

Have someone else sit inside your car and apply pressure to the brake pedal as you observe the brake fluid reservoir. If you notice fluid swirl or bubbles forming in the reservoir as they press on the brake, then your master cylinder is not functioning properly and will most likely need to be replaced.

Step 3

Inspect the area around the master cylinder for fluid leaks. If you notice any brake fluid leaking out of the master cylinder, then it is not functioning properly and will most likely need to be replaced. However, if the fluid is leaking out of nearby brake lines or tubing, then your master cylinder is probably not the problem.

Step 4

Apply pressure to the brake pedal until it comes to a stop and then hold the pedal there, sustaining the pressure. If moments after the brake pedal has come to its initial stop it begins to drop down again slowly, then the master cylinder is not functioning properly and will most likely need to be replaced.



Determine if the brake master cylinder is the problem. If there are no fluid leaks at the master cylinder, no swirl or bubbles in the brake reservoir, and the brake pedal does not slowly descend with constant pressure, then the master cylinder is working properly.




then go through the hydraulic section of this page Diagnose brake drag


That should narrow down the problem

not sure if it's the cause of your problem, but i don't think that's the bleed order according to the rave manual. perhaps there's a reason why they say rf - lf - rr -lr.

Try to clean and grease the guide pins on the calipers.

Good stuff. I'll make sure to check that. Thanks


I'll give that a shot. I guess I was going off the answers others have done with the sequence I tried. I'll give the other order a try and report back. Thanks!

Checked these when I replaced pads 3 months ago. All were good. Thanks!

I'm curious to know why this bleed sequence is the way it is.
Simply because I've always been taught to bleed farthest from the master cylinder first, closest last.

Usually what causes calipers to stick is interiorly swollen soft brake lines. If you haven't replaced them yet, it's overdue. Don't forget the two short ones on the D/S wheel well under the ABS unit. Old brake fluid absorbs moisture over time and it causes the rubber inside the lines to swell and hold pressure either to or from the brakes. That's why it needs to be flushed with fresh fluid every few years.

I thought the rave sequence was a misprint. A few on here said it was because the abs unit changed things. Bottom line is that my 90 year old mechanic put it on a rack. The correct order is RR, LR, RF, LF. I don't give two ****s what the race says. This old bastard has forgot more about cars than the rest of us will ever know.

And spray the pistons. Probably a dirt ring around the seals preventing them from retracting properly