I want to find out if its my brake booster thats bad or my master cylinder. when the engine off off the pedal will get hard with a few pumps. when engine on it becomes sponge and i will not start to stop until the pedals half way to the floor. if i quickly let off the pedal then press again i will get normal breaking and it will not be sponge anymore until i let off the brakes again. i have bleed the brakes multiple times. could this just be a master cylinder issue or brake booster? i dnt want to spend money on a booster when its the master cylinder and vise versa.

 

as long as you have no signs of leaking fluid and brakes work,sounds like you need to adjust your back brakes up

 

Are all xj brakes kinda hard to get to stop
I have other cars that stops alot quicker than my jeep like if I have to stop late at a stop like ill wind up in the middle of the intersection before it comes to a stop

 

early year xj are very under powered in the booster area up gradding to the new style booster will greatly improve stopping power

 

I just want to get a better response out of the brakes I have

 

yes, it sounds like your master cylinder is shot.
you can replace it with a rebuilt, or junkyard part without removing the booster. it's not a hard job at all.

 

its not the brakes it the weak pressure that the booster applys to them i have stock brakes but upgraded booster from u pull it grand cherokee 100 percent better stopping for less than 50 dollars and a hours work...

 

bad master pedal will slowly sink to floor when constant pressure applied...

 

also ive noticed that my abs will kick on real easy. especially off road and in the snow. there was only maybe half a inch of snow on the ground and i started to slowly press the brakes to stop and the abs kicked on as if i was panic stopping

 

always start with simple repairs

 

im going to def try that tomorrow. i noticed that the back brakes always make a popping sound and my ebrake doesnt work

 

after adjusting brake theres a adjuster under xj right above drive shaft to adjust for e brake

 

i just did a master in one of my tj's.
exact same symptoms.
brake pedal does fade, if you slightly let off the pressure.
good pressure if constant on the brake, no fade.

 

Ranger does the pedal creap down when you hold pressure to it

 

I need to see if mine does