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Brake help!!!

Wwildman

NAXJA Forum User
Location
Garner,Nc
Well I finished doing my braided lines and replaced the brake pads .
I gravity bled the brakes .After the fact I found out my M/C and booster were leaking so I had another and installed it .now the brake pedal is almost to the floor .I also ran 3 32 oz bottles of brake fluid through it . It has zj disc brakes on the rear with stock m/c and booster .
Any Ideas ?
it is a 88 xj with stock m/c ,and disc brakes in the rear .
 
I've seen M/C-boosters with different length booster push rods.
 
If I am reading your post correctly you replaced the MC and Booster after you did the braided lines and pads? Did you bleed the booster seperately before installing it? If not you might still have a large ammount of air trapped in the system. Its also possible that the booster pushrod length is incorrect like NEWYXJ mentioned. They are usually threaded on one end and need to be set to the same length as the one you replaced if not reusing the old one.

When you did the lines did you get the calipers mixed up and swap them side to side possibly? That would put the bleeders at the bottom not letting the air out of the system.
 
I've seen M/C-boosters with different length booster push rods.
Checked that as well all rod lengths the same .
I would like to add the master and booster are used and I do not know the condition .I do know the booster does not leak and rthe front brakes hold but the rear do not stop the vehicle .
 
Is it possible that that master is bad? The other option that I can think of is that the propotioning valve is causing problems. I have read posts that guys modify them somehow when they do the rear disc swaps. The original design is made to hold some pressure in the rear line so that the wheel cylinders don't take as long to react when you hit the pedal. With disc you don't need that to happen.
 
1. Pull the MC and bench bleed it, you will quickly know if it isn't working. I won't use reman MC, always NEW--I'll reserve comment on installing a used MC.

2. Check Go Jeep's website and lunghd.com on mods to the proportioning valve.
 
^ what he said. take off the master and bench bleed it. start there.
 
Well I ordered a 95 zj booster and master I am going to install and do the mod for the prop valve
 
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