1988 jeep brakes

I bled my rear brakes but cant bleed the front because the little bolts are rusted on.

Im not sure if thats the problem im having but I seem to have great front brakes, and rear, but there is not much pressure. Its not spongy either.

So If i push on the brake it will go 3/4 the way down easy and then the last 1/4 stroke it will go from soft to locked up, its gotten a little better since ive been driving it. Now they wont lock up unless I want them to.

I am 16, so I dont know much. Could it be the master cylinder? Nothing leaks, ive rebuilt the wheel brake cylinders in the rear, and new brake pads

Sounds like you have old (contaminated) fluid and/or air in the lines if the pedal is acting like that. What does the fluid in the master cylinder look like, is it clear or dark yellow? On my 88 the brakes are fairly weak compared to new vehicles but the pedal is fairly linear and at real slow speeds like pulling out of the garage the brakes grab as soon as I get on the pedal.

If the front bleeder bolts are rusted I would first try soaking them with PB Blaster every day for a week straight and then heat the hell out of them with MAPP gas before trying to remove. Steady, slow pressure to try to get them to budge and then replace the bleeder valves before you put them back in - they have them at NAPA or Advance in the Help section but you'll have to ask what thread size you need, I haven't replaced my fronts yet and am not sure.

Worst case you replace the front calipers, they're not real expensive, I just looked them up on NAPA and their cheapest ones are $20 with a new bleeder screw and they're $43 with pads, that's a deal and a half!!

Get new copper brake line washers when you replace the calipers, and pick up a Haynes or other service manual so you know the torques if ya don't have one. And make sure the bleeder bolts are at the top of the caliper when you re-install, I've found that a lot of times the stores have the model numbers wrong in their computers so you can't rely on them to tell you which is right or left, you have to look at them and make sure they're correct.

And finally, don't be afraid to ask another jeeper to stop by and help you bleed them, so you know they're done right! It's obviously real important that ya get it right the first time.

Good luck!
CR

Thanks a bunch.. I think im going to go get some PB blaster and soak them and the cat. converter bolts for a week, i got a propane heater so I will try that ( i think it only burns at like 1500 instead of a mapp at 2500. The fluid is good my dad says (he is good mechanic but he wants me to work on it, and ive been busy lately so he wont look at it unless I help him.

Ill ask around on the thread size.

I'll vote for the second option-- replace the calipers and bleed everything. I would shy away from hitting the brakes with the "smoke wrench" as the seals in the calipers don't take well to it (they're just rubber)

safe plan

be sure to lube the caliper mounts with high temp brake grease to aid movement on the mounts and as said before, make sure you replace the copper washers at the banjo bolts for the hoses.

banjo bolts?
And what is hi-temp brake grease? Is it the black thick grease in a tube

CustomCrawler said:

banjo bolts?
And what is hi-temp brake grease? Is it the black thick grease in a tube

Click to expand...

The banjo bolts are the ones that the brake lines use to bolt to the caliper, copper crush seals ALWAYS need to be replaced. The high temp grease is $1.00 for a small pack (thats all you need really) and its goes on the caliper slide bolts and the caliper piston face, they get really hot when braking, it prevents noise too.

I don't know what year/miles you xj has, but I would take a good look at the front rubber brake lines. They can help make a soft brake pedal feel becuase they can expand when they get old, not to mention burst. They also come with the copper crush seals! :yelclap: