Bad brake problem, please help!

[broke30]

Okay well an update:
I replaced ALL four calipers again, this time with brand new ones. The brakes locked completely, all four of them. So if I need a new proportioning valve then I need a new master cylinder? Any good places to find one? Oh and BTW, the abs fuse was pulled when all of them locked up. So I guess its not an abs problem....
Max

[Massive Lee]

When was last time the brakelines were changed? Are they still the rubber one? It is posssible that being old, they are clogging from the inside. They become like one way valves, which keep the pistons from retracting. So, they drag continually...

[broke30]

When was last time the brakelines were changed? Are they still the rubber one? It is posssible that being old, they are clogging from the inside. They become like one way valves, which keep the pistons from retracting. So, they drag continually...

Wouldn't fluid not be able to move in and out thought? Cause they bled fine...
Max

[Massive Lee]

The pressure that the MC can apply to push the fluid thru a clogged line, is much higher than the pressure the caliper's pistons can exert to push back and fully release the brakes. Clogged/swollen brakelines act like one-way valves.

I still find strange that all four calipers have problems.

[broke30]

Yes as do I, I am going to purchase a Master Cylinder and see how that works.
Max

[netcsk]

Yeah. Master cylinder is most likely now. When it was just the rear, it sounded like it could be the valve because the valve only runs with the rear brakes.

I'm actually having this same problem with my car right now but I have brand new lines and a rebuilt master cylinder.

Next time they start to drag, when you get to a complete stop push the pedal down hard. Do your brakes release? If so, then yours is acting just like mine.

[2002maniac]

i had a problem similar to this one a few months ago. It turned out that the pushrod inside the booster had bent and would not return.

Iput a new booster in and it was fine. The booster was not as difficult a job as I had expected.

[broke30]

I replaced the master cylinder and still have the problem slightly, sounds like I have the same problem you did 2002maniac. They still drag a bit until I pump them a little, guess I need a brake booster too! Anyone have one for sale?
Max

[netcsk]

make sure you get the same kind that you currently have (ATE or Girling).

[netcsk]

Old thread...

I just got around to replacing my booster and it completely and totally fixed the problem. I didn't see the problem with the booster, but the replacement fixed it.