What did you do to your XJ today??
Senior Member
Joined: Jan 2012
Posts: 661
Likes: 1
From: Federal Way, WA
Year: 1997
Model: Cherokee
Engine: 4.0L I6
Last night I did a lot of reading and research about a system I've always thought was quite simple. However, the Brakes on my XJ have got me stumped. After developing a spongey pedal I went with the typical "look over everything for leaks" troubleshooting. When I didn't find anything leaking anywhere I logically assumed, since it did have a little pedal at the very bottom of the stroke that the Vacuum Booster was bad. I swapped that out and had no change so I figured the piston cup in the MC was letting the fluid by hence the spongey pedal and no leaking. I was just days away from a weekend campout and wheeling run 200 miles away in Elbe so i threw the new MC at it. Also in the process I found my rear brakes to be totally inop. and the drums were packed tight with mud. I clean it all out and installed new wheel cylinders and brake shoes to both sides. Here is where I started getting P.O.'d. After all of that I had the same spongey pedal with the Brake dash light coming on. The brakes would always stop the Jeep but at the very bottom of the pedal stroke and with fast pumping would pump up. The next brake application it would go right back to the floor with the brake dash light on again. I did a little research online and found procedures for upping the pressure to rear brakes after an axle upgrade. So, i removed the little rubber cup from the piston in the Proportioning Valve and then bled the PV and then bled the brakes. This at first appeared to fix the problem. I had a nice hard pedal while sitting in the driveway. As soon as I took the Jeep out of the driveway for a test drive at the first stop. The pedal went spongey, brake dash light came on and the jeep finally stopped with the pedal on the floor, again. This brake discrepancy has really got this backyard mechanic stumped. If any of you guys have heard of anything that you know that will fix this problem then please let me know. My next step in troubleshooting is going to be to remove the brakeline going to the rear brakes at the PV and at the rear flex hose and blow it out with compressed air. Then open the bleed screws to left then right rear brakes and blow them out individually with compressed air. all i can think of is that I've got some crud or rust in a brakeline somewhere in the system that is blocking proper operatrion and keeping air in the line somewhere.
CF Veteran
Joined: Sep 2010
Posts: 1,562
Likes: 3
From: Spanaway
Year: 97
Model: Cherokee (XJ)
Engine: 4.0
Originally Posted by BuckB91XJ
I appreciate the tip. Right now I'm taking any and all.
Last edited by mudderx; Aug 16, 2012 at 11:49 AM.
Member
Joined: May 2012
Posts: 209
Likes: 0
From: WoodinVille
Year: 1994
Model: Cherokee
Engine: 4.0
Originally Posted by BuckB91XJ
I appreciate the tip. Right now I'm taking any and all.
CF Veteran
Joined: May 2009
Posts: 1,844
Likes: 4
From: Glen Burnie, MD
Year: 1994
Model: Cherokee
Engine: 4.0 H.O. K&N, Borla headers, custom down pipe, magnaflow hi-flo cat, flowmaster to turn down tip
how are the pistons on the front calipers? are they sliding and functiononing properly? are the slide pins that the caliper bolts to greased? i have seen seized up caliper bolts give the same symptoms you are seeing.
when you replaced the booster and master cylinder, did you go with stock replacement or with the Grand Cherokee upgrade Buck? cause i had crappy brake pedal feel with my bigger tires till i did the upgraded Master Cylinder and Brake booster
when you replaced the booster and master cylinder, did you go with stock replacement or with the Grand Cherokee upgrade Buck? cause i had crappy brake pedal feel with my bigger tires till i did the upgraded Master Cylinder and Brake booster
Banned
Joined: Sep 2011
Posts: 138
Likes: 0
From: Sisters, OR
Year: 1989
Model: Cherokee
Engine: 4.0L stock
That's cheap....lol
3M 38808 been using it for years and holds great. I guess as long as you do it right the first time....my dad has used it since his late 20s and never had a complaint.
http://m.oreillyauto.com/mt/www.orei...0019&ppt=C0326
3M 38808 been using it for years and holds great. I guess as long as you do it right the first time....my dad has used it since his late 20s and never had a complaint.
http://m.oreillyauto.com/mt/www.orei...0019&ppt=C0326
Senior Member
Joined: Mar 2012
Posts: 658
Likes: 0
From: grand rapids
Year: 97
Model: Cherokee
Engine: 4.0
Originally Posted by timber.tiger
Thanks for the tip!
CF Veteran
Joined: Aug 2012
Posts: 1,539
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From: ks
Year: 1998
Model: Cherokee
Engine: 4.0
Banned
Joined: Sep 2011
Posts: 138
Likes: 0
From: Sisters, OR
Year: 1989
Model: Cherokee
Engine: 4.0L stock
Having issues with my power steering not doing its job, meaning when I push in the clutch and brake for a turn, the steering locks up... but I can overpower it. Keeping the RPM up while cornering eliminates the problem. I replaced it exactly one month ago, but it's already acting up. Replacing it tomorrow and will go from there. I've got the time down to 15 minutes to remove... gonna see how fast I can install and bleed it!