mwdouglas

my 90 doesn't have a brake booster but instead had an electric pump i have lines coming out of the master cylinder going to this pump then comes it of the pump to the divider going to the wheels i was told when i bought it that it has the tow package and i have an abs light that's on this pump makes a grunting noise every min or so is this normal if not what could cause it

ZachsXJ

you should still have a brake booster. the electric pump is part of the POS ABS system that was on the 1st Gen XJs. From what I've heard its crappy enough to be worth just removing and converting to a non-abs system.

ol"blue

You've probably got the hydro-boost system.

_StationWagon_

We found one like that in a junk yard full of C-for-C XJs in PA last month. The guys had never seen one like that before & several of them took pictures. They started to take it apart too, to see how it was put together (guys!). I think someone even kept some parts in case someone like you might need parts or info. If you need more info you could go to the NAXJA Forums website, go to the North Atlantic CHapter and ask your questions.

Might get help there.

azcheapjeep91

you have the same sys i have on my 1991 there is no booster the pump supply the boost kinda like a hydro boost sys that uses the power steering pump but this is better don't rob power from motor you probley got 4 wheel abs ,the pump should only come on when you step on brake pedal if the pump is coming on while driving you may have a leak in the sys or a short ele in system , if pump sound bad rattling my just of come lose from the mount or you got a bad pump . hope this helps

mwdouglas

it comes on when the brake is applied but it also comes on intermittently, prob every min or two for about 30 sec then goes off. im just not familiar with a braking system like this and wasn't sure if it was normal or not

chastings

Sounds like you have the Bendix 9 brake system; it utilizes an electric pump and accumulator for power assist instead of your traditional brake booster. This was an early attempt for chrysler with regards to abs. It was prone to failure, as a result had a recall and replaced lot's of stuff (still failure prone). The abs light should not be coming on and the pump may be cycling to frequently, not sure. Typically, mine came on once every 3-4 brake applications (til it failed last Monday). You can go to a JY and salvage a complete master and booster to convert, or just go back to chrysler for repairs. I've heard horror stories, but you might be surprised. I read that there was a lifetime recall for the pump and accumulator only; however, I took mine in and was told they would fix anything with regards to power braking under the recall (does not apply to wheel sensors). I got a call from chrysler yesterday, they replaced the pump free of charge and my Jeep is back on the road.

SeriousOffroad

Chastings nailed it.

My son's 91 had that same POS system on it. Scary at best since it worked when it damn well felt like it.

We ripped it out and replaced it with a traditional brake system.

mwdouglas

cool thanks for the info i will do a search and see if someone has posted on here the procedures on doing the conversion to the reg power booster set up

RENIXBEAST

I would have it replaced (If Chrysler will do it free with recall), then convert and sell the new parts. HEHEHEH hustle the system.

mwdouglas

with this recall is it for any owner i bout mine used and im like the third owner so would it still apply to me plus mine is lifted with 33 will that void the recall

SeriousOffroad

Recalls cover the the vehicle regardless of of the owner.

mwdouglas

cool will have to check into it then thanks for the help

chastings

The recall will apply to the vehicle irregardless of the current owner. Initially, the recall warranted the entire system within 10 years of vehicle manufacture or 100,000 miles. I'm sure yours has already been in for service multiple times, as the original piston pin seal in the actuator was EXTREMELY failure prone (prior to recall). After complying with the original recall, the lifetime warranted parts are only supposed to be the pump and accumulator, but, like I said earlier, Chrysler told me last week that they would guarantee the entire system. I planned on doing the switch as well, figured by taking it to Chrysler they would tell me which part was bad and I could sell the remaining good parts on ebay. Imagine my surprise yesterday when they called and said they had already fixed it and wouldn't cost me a dime. Looks like I'll be sticking with the Bendix 9 a bit longer? Good luck

posjeepxj

on the bright side atleast you have the stronger u joints in the front axles, and no vac disco