90 Xj Abs Weak Brake Pedal

[joe88xj]

I DID SOME SEARCHING BUT CANT FIND A DEFINITE ANSWER, my buddy has a 90 xj with abs, theres an electric booster motor on the passenger side firewall how often should it turn on? his comes on every couple minutes, also his brake pedal goes all the way to the floor, his brakes work well they stop just fine but the pedal can be pushed straight to the floor. thanks in advance guys!

[Bones]

If the pump is cycling that often, I would venture a guess that the accumulator is bad. In addition, if the cycling is happening without using the brake it sounds even more sinister. The Bendix system is a real POS. Check out recalls at NTSA and info at The Chrysler Products' Problem Web Page.

My advice is to dump the ABS and install a non-ABS system. The Bendix system is a real deathtrap IMHO.

Yes, I put my money where my mouth is:
Uninstalling the OEM Anti-lock Braking System.
Previous thread on Bendix ABS removal

Bones

[Greg Smith]

On my 89 with that abs sytem the pedal has always engaged much closer to the floor than other cars. The pump should only run after 2 or more applications of the brake pedal (after the initiate runing of the pump at startup of course). If more often or if it runs even without using the brake pedal then your accumulator is probably bad. Its about $100 at jeep and you can install in twenty minutes. I did not even have to bleed the system. But you must apply brake pedal about 50 with igition off to remove the high pressure from the system before removing the accumulator and installing the new one. A strap wrench or oil filter wrench works on removal and installation w. another wrench and some wood wedged to hold the bottom of the accumulator block steady during the procedure. Greg