What do you suppose it is when, I mash on the brakes and they don't have enough stopping power? Pads are good, It feels like there is good pressure, They work O.K. around the city but if I have to mash on 'em it doesn't stop hard. It doesn't feel like an abs problem or anything.

 

checked your fluid lately?

 

Air in the lines. Bleed bleed bleed!!!!!!!!

 

fluid is full, I will bleed the brakes or perhaps give them a complete transfusion....

 

what size tires are on it? mine does the same. i've tried bleeding them out many different ways. even did the transfusion thing.

but just remember not to drain the MC dry or you'll have to bench bleed it.

 

Sounds to me like it the typical XJ brakes... I'd check the rear brakes first, those wear out and you can barely notice, but all during that time, you're taxing the front brakes harder and harder, and they're not all that to begin with. I'd probably be willing to bet the front brakes are a bit glazed over too...

 

Does your XJ have ABS? If it does the ABS pump and actuator are covered for life. If it doesn't swap in a later model booster and master cylinder I believe 94 and later have the dual diaphram boosters.

Since swapping the ZJ rear disks in mine stops alot better, but still not as good as I want so I'm going to be upping the size of the front brakes to the WJ brakes and steering.

 

Side question-what do you mean the ABS are covered for life? Some sort of Daimler/Chrysler warranty or how do you mean? Interested to know...

 

I'm supprised that no one mentioned the power brake booster. Maybe it doesn't have one because of the ABS? Some Fords are like that- the M/C bolts up to the hydrocomputer/electronic booster. (not to be confused with GM hydroboost- from the P/S pump)

If you have power brakes- and I'm sure you do- if it requires massive amounts of pedal pressure to get it to stop...look at the vacuum assist/ power brake booster (it's the black round thing the M/C bolts up to. Also check the little black 90* one way valve that the vacuum line runs into- vacuum can come in, but not out. pull if off and suck on it.

A way to test the diaphragm inside would be to let the engine run and build vacuum. Shut it off, wait a while (maybe 30 minutes), go back in, and press the pedal down. You should hear a whoosh sound- it's vacuum escaping. This will tell you if the diaphragm has a cut it it. If you don't hear it, it COULD be bad. A bad booster can have two different sypmtoms.

I had one go out on my 84 Cheif- and it was like a push button vacuum leak- push the pedal down, and the engine would start running like crap. It still worked, however.

 

Usually after i check my brake fluid i adjust the rear brakes, either with a drum brake adjustment tool, or by finding a big steep hill i can back down and jab them hard and tight. That usually makes a discernible difference in feel. Good Luck!!