Brake caliper binding/sticking after hard braking

[abscate]

Give them 28 seconds of heat with propane and they will come free just fine. Very high quality on the masters on this car.

I’ve got a used one I think if you want to save half the bucks, at least.

I sold a older one but I think I have a like new one off my first parts 1999

[Milehighv70xc2]

Update--
I dont need to be driving the car to get it to stick and it doesnt matter if the brakes are hot or cold.

Just lightly pressing and holding the pedal down will cause it to stick. Dont have to pump them to get it to stick. The pedal gets more firm when it sticks as well. Car doesnt need to be to on or running to stick.


Once it is stuck, with the car on or off, I can watch the fluid very very very slowly return and raise the level in the reservoir as the calipers becomes unstuck. Takes a minute or two.

Removed abs fuse, no different.
Unplugged abs module connector, no difference.

The fluid flows out to each caliper the same at all four corners. Confirmed from bleeding the brakes. Its just the fluid is not returning from the right front. Seems something in the abs block or master cylinder is clogged. The fact the fluid flows out just fine is kind of confusing.

Still sound like a master cylinder?

Abscate- thanks for the offer on the MC. I might take you up on it. I will PM you if I decide to go that route

[pgill]

Don forget to change the brake hoses.

When the hoses get old they can act as a check valve.

[pgill]

Also you mentioned that you lubed the slide pins.

Did you use a Silicone based grease?

If you use a petroleum based grease then the bushings can swell and cause brake binding.

I use CRC Silaramic Grease

It a silicone grease with ceramic particles.

It works really well.

Silaramic.jpg (60.57 KiB) Viewed 1116 times

Good luck

Paul

PS If a new brake hose and Silaramic grease don't work then I would replace the master cylinder.

[pgill]

If you use a wheel bearing grease then you will need to replace the bushings on the caliper when you switch to Silaramic (or something similar)

[Milehighv70xc2]

Grease is a Bosch branded synthetic. Not sure if it is silicone. Came with the Bosch brake pads I put on another car.

New brake line

Update-- I was able to get it to lock up with the car off. I applied pressure to the pedal for about 20sec and it locked up. It released within 20sec. Unlike when it happens with the car running and it takes a few minutes.

I unplugged the abs module connector hoping that is was a bad connection with one of the pistons in the abs block, Didn't change the problem at all. Seems to be a mechanical problem.

Sounds like a master cylinder is next.

Thanks everyone for your replies. I wont be able to work on It until monday. I will update the post whenever I fix the problem.

[kallekula]

Sounds like the ABS? Not the electronic part but the "block" with the motor on it.

[Milehighv70xc2]

Kallekula- I would agree since all for brake lines run separately from there. From the master the fronts run together and the rear run together to the abs block. I have been thinking something is clogged in the return port. I dont know very much about how that all works but from my research it seem pretty straight forward.

The master is a much cheaper and easier to replace... if that's the problem, Hmmmm

[FLXC90]

You could remove the control module from the ABS unit, and maybe fool the pintles with a magnet to activate the different ports to the manifold? Don't know if it would reveal anything though. And check your hose on the affected wheel, it may not look bad, but the core may be collapsing when pressure reduces (relative vacuum).

[kallekula]

Kallekula- I would agree since all for brake lines run separately from there. From the master the fronts run together and the rear run together to the abs block. I have been thinking something is clogged in the return port. I dont know very much about how that all works but from my research it seem pretty straight forward.

The master is a much cheaper and easier to replace... if that's the problem, Hmmmm

Exactly, you have two lines running from the master cylinder to the ABS. wouldn't you have two brakes locking up if it was the master that was faulty?