Hello everyone! I have recently purchased another 98 disco l with 137,xxx miles on it and the body is in pristine condition! However after I drive it roughly a mile or 2 it starts to slow down so I need to floor it to get it to go faster until it just stops completely. After a few hours it is capable of driving. I had found out that it is all 4 brake calipers seizing and locking up the car past the point of movement ( so I think).I had thrown it in the garage to change the blown head gasket, I had also placed a new master cylinder on it. After replacing everything it started driving fine other than a stif brake pedal and a hard stopping capability. That was 2 days ago and now it's starting to seize again. My question is this, has anyone ever experienced this problem before?(and) might this have to do with the infamous ABS module?

 

Was it an aftermarket or OEM brake master cylinder?

 

Master cylinder must be OEM.

 

It was an aftermarket from autozone

 

Sorry, an Originial Equipment Remanufactured (so it says on the box)

 

By any chance did you or the previous owner replace the brake light switch recently?

 

I have one that is acting the exact same. did you ever figure it out?

 

to rule out ABS and further the process of elimination, pull fuse 8 to disable the ABS pump

 

wrongway1 : not that I am aware of
wkburns: Yes I did! I pulled the abs fuse from under the hood and I also replaced the master cylinder. However, the brake pedal is still stiff and takes a little while to stop (possibly bad booster or air in the line still). Does anyone know how to bleed the proportioning valve if it's possible?

Thanks,
Flip

 

You need to check the pushrod in the front of the booster where it engages the master cylinder. If the adjustment is such that the rod applies pressure on the master it blocks the port that allows fluid to return freely to the reservoir. Once the brakes heat up and the fluid expands it applies the caliper pistons and stops the truck. Make certain there isn't pressure applied from the rod coming from the brake pedal itself. It's possible the PO tried to adjust for the brake problem.

Was the original master cylinder even bad? Perhaps you only had a bad booster from the start.