Not sure if this as been discussed, I did run a search?

My 1998 Disco brakes start to tighten as I drive till it is so bad it will stop the car! If you let it sit for about an hour you can drive it again. We pulled off the tires and checked each caliper and it is like someone has a foot on the peddle! The peddle also get tighter like it is building pressure. We tried to empty and put new DOT 4 oil and bleed but still the same? The ABS light as been on since we owned it, but I did try pulling the fuse under the hood for the ABS and still same thing!

Brake pad are also good, almost new.

Any help please

Thanks

 

You have a bad caliper, it is sticking.
www.autosportsunlimited.com
Buy them in pairs and replace both calipers on the same axle at the same time if you can afford it.
If not then replacing just the bad one is better than nothing.

 

Is it all four brakes? (new to me)

I think to disable the ABS, you need to pull (2) fuses, guys do it, but I'd need to know why first.

keep us posted, please

luck,greg

 

To disable the ABS on a DI you pull only 1 fuse, and that is the 30A ABS pump fuse from under the hood.

 

I've never heard of D1 ABS causing brakes to drag, usually it's just the opposite, they fail to stop you.

 

No on the calipers they have been checked for proper operation, besides for all four to fail at same time and it starts applying the brakes in transit with my foot off the brakes? Pulled the fuse for the pump & it was a no go. I am leaning towards the Master Cylinder, even know that most fail by dropping the peddle to the floor, my thinking it is letting servo unit build air and putting pressure on the master? Also I doubt the Pressure reducing valve would cause, but you never know.

 

In your first post, you said brake(s) plural.

The brake servo is supposed to be under an engine vacuum, the only connection between it and the master cyl. is mechanical.

Therefore, for the brake servo to apply your brakes, it would have to be pressurized, which I think still wouldn't do it, as the internal travel is limited.

I suppose the internal spring in the servo could be doing/not doing something crazy, but that'd be a new one on me.

The proportioning valve has no external forces acting on it.

keep us posted, please

luck,greg

 

OK, had sometime to play with it again!

I do think it is the servo now! I got the brakes to tighten then lock, then when I loosen the nuts on the master to the servo, the brakes free up and work good! So my new question, does the servo unit on a Disco 1 with ABS have an adjustment? I did not see it in the rave manual?