Help with brakes...

I have an 88 XJ that is pulling to the left whenever I hit the breaks. There is also a considerable lag in breaking. I thought that my front right caliper was sticking.
I looked at my brake fluid and it was disgusting!! But I just had my brake fluid flushed about 4 or 5 months ago. I used a c clamp to push the piston back in on the front right caliper with the bleeder valve open, but no brake fluid came out and the piston slowly came forward again after I removed the clamp. I then tried to vacuum bleed that caliper and nothing but bubbles came out.
There are no signs of heat to my rotors and my pads were both pretty decent. What does this sound like to you, and how could my brake fluid be so dirty after such a short time??? Thank you for any help you can offer.

Sounds like you are sucking up contamination from somewhere - probably brake dust, from the sounds of it. Check for a leak at the caliper piston boot or that the banjo bolt on the back of the caliper is not loose.

Since you are already in for a brake bleeding, might as well take out the bleeder screw while you're at it and inspect it and its seat. Make sure the bore in the bolt is not obstructed, and that there is no defect in its mating surface in the caliper. You'll have to remove the tyre to get a good view of the problem, so be warned (actually, it's not that hard.)

Also, check that you are not losing the seal at the lower crimp on the brake hose. If/when you get solid fluid from the bleed, pull a vacuum and manipulate the hose around the crimp to see if it pulls air. If it does, replace the hose.

Let us know how that works out, and if you need more ideas...

5-90

You were right to worry about cruddy fluid. Get a buddy and keep bleeding the brakes until the fluid comes out clear or you will end up replacing calipers pretty quick. I gather you didn't see any signs of leaking fluid, correct? I would check the gasket on the master cylinder. If you get moisture in there, it always seems to migrate to the calipers and it will make a mess of your fluid.

The part about compressing the caliper piston and not seeing any fluid go back up into the master cylinder seems to say there was no fluid in the piston. If there is no leak and the piston is good, about the only thing that could cause that would be getting water in the piston, getting it hot enough to boil and the fluid was already forced out by the steam.

Thank you so much for your ideas!! I am pretty new to this site, but it has been soo helpful to me - so thank you!!

I had another question for you guys, do you think the proportioning valve may be causing my brakes to lag?? Even before my XJ started pulling to the left when I hit the brakes, I noticed a considerable lag in stopping. I am going to be replacing my rotors, pads, and calipers but I am wondering if the proportioning valve should be something I replace as well. Is there any way to test if my proportioning valve is good or bad? Thanx again!!

dont worry about the proportioning valve yet- stick to the easy stuff.

all in all, it sounds like you have just plain bad dot3 with a watery mix that boiled- you may not have to replace your calipers...but its not a bad idea either.
Once your fluid starts to change over to gunk, you have to bleed it all out--- all of it- followed by new fluid, without sucking in air. While your at it, bleed the rear as well. Use lots of fluid- dont skimp, buy 3 cans.

in your case, pulling to one side was probably nothing more than air in one side and fluid in the other(since you ruled out a sticky caliper), or a glazed pad on one side....other possibles, but Ill bet on those.

after you do a bleed, you may notice that the brakes dont work-ala~foot to the floor- you * may* have to reset the proportioning valve. Use both feet and stand on the brake pedal untill you hear a loud click.

I have never heard of resetting the proportioning valve. Can you explain to me how this works?? Is the car off or on when I am pushing the pedal to the floor?? Also, what exactly is the clicking I will be hearing? This is very interesting to me. Thank you!