92 4x4 brakes dragging, locking up

[bcripe]

My dads 92 with 500k+ miles is having a weird issue. It starts out fine but within 10 miles the brakes start dragging to the point where the truck will not move. Seems to be only the front. He cracks the line to the front brakes under the master cyl, relieves pressure and goes another ten until it happens again.

Does anybody have any ideas? New master cylinder?

Thanks!

 

[raevenzero]

That's not weird at all. I've dealt with this a few times on different vehicles. The likely cause is water moisture in the brake fluid. *No guarantees though*

Over time, brake fluid can draw in water. This water accumulates in the calipers and as they heat up, the water boils and expands. This forces the caliper pistons out and applies the brake.

If they seem to be fine after the truck sits for awhile, this is probably the issue. Perform a full fluid flush. It should be clear when done. If it still looks brown, keep flush. Also, it doesn't hurt to clean and grease the caliper pins that go through the pads.

 

[dkdnt232]

My dads 92 with 500k+ miles is having a weird issue. It starts out fine but within 10 miles the brakes start dragging to the point where the truck will not move. Seems to be only the front. He cracks the line to the front brakes under the master cyl, relieves pressure and goes another ten until it happens again.

Does anybody have any ideas? New master cylinder?

Thanks!

I had a similar issue with a 1997 4runner. I replaced calipers, abs valves, complete fluid replacement, and master cylinders. I always thought the problem was in the front portion until one day I bled the rear line when the brakes were locked up.

Turns out the booster was bad and causing the brakes to apply on their own. I replaced the booster and it worked like a charm afterwards.

Good luck!!

 

[bcripe]

Thank you all. We are working on it tomorrow... Ill let you know what we find.