Brake grabbing

[Mdl]

05 liberty 150000mi. I’ve been in and out of the shop trying to isolated a brake issue . After replacing a booster, front calipers, hoses and all lines to the master cylinder the brakes will still grind you to a stop and smoke, I can’t seen to get 20 miles down the road. Everything’s fine starting out than out of nowhere it starts to slow down and gradually stop and the pads are smokin! No rhyme or reason stop and go or 60 mph. Let it sit and cool off then your down the road. Also there is a brake line connection point just below and left of master cylinder, what is it? I know the truck has no abs but this is in the same position as the pics I’ve seen of the abs. could this part have restrictions in it. I’m tired of having to put it in the shop and waiting for someone to scratch their head.
Michael

 

[Ksat]

Which wheels are affected/getting hot? When things are cool, you may want to jack up both front wheels and spin each individually by hand, then jack up both rear wheels and do the same, to see if any brake feel like it's dragging. Trans in neutral.

If no wheel feels like it's dragging and all wheels are being affected when the problem presents itself, it may be that the pushrod in the master cylinder is too long, or otherwise is not being allowed to fully retract when your foot is off the pedal.

Water contamination in the brake fluid can also be a cause.

 

[turblediesel]

A bad master cylinder can do that, on an old Fiat anyway. Next time it happens feel the calipers to see if one is hotter than the others, if so it could just be that caliper causing the problem. Otherwise it's the master cylinder. Keep a caliper bleeding wrench in your jeep and you can open and close the bleeders to get it home. That'll let air in the system and adversely affect braking so drive accordingly, don't use the brakes, and be ready with the emergency brake, if it works. Or just have it towed.

 

[JeepJeepster]

When this happens, if you stop and jack up the Jeep, is the wheel with smoking brakes still hard to turn? If so, what happens if you loosen the bleeder screw? Is it still hard to turn? If so, you simply have a bad caliper (again). If it loosens up, you have something upstream causing the issue.

 

[Mdl]

So far both fromt lines and calipers as well as booster were replaced.

 

[JRB]

With a tough to troubleshoot problem, and how bad quality control is on parts, I always verify if the replacement parts are in working order. I've got enough bum new parts over the years to be skeptical.

 

[DadOSix]

So far both fromt lines and calipers as well as booster were replaced.

Problem on both sides when it acts up?

 

[Johnny O]

Other than changing pads and the occasional caliper, I freely admit disc brakes are one of the few things I pay a shop to handle. Something this drastic, that’s my advice- take it to a brakes shop.