Brake problems

[Ruepart Hoaxley]

Booster?


Sent from my pay phone in Chechnya

[armadasx]

I havent adjusted the drums since i put those shoes on.the drums and shoes were both brand new.when.i did the.brakes in it a year ago.

[HeavyMetal]

Booster?


Sent from my pay phone in Chechnya

researched this and it would appear a bad brake booster actually creates a hard high pedal. saw this posted a lot, so I guess that cant be it. i will have to give the other ideas a try.

[ct67_72]

Yeah, no way a booster would make it soft, or affect the rear brakes.
The pedal is definately soft because of whatever is going on in the back.
Will, when you bleed them, so you get a good squirt of fluid out, and does the pedal drop noticeable once the bleeder is open, and does it drop fast?

[HeavyMetal]

Yessir, we bleed it with the jeep off and it feels like any other time i have bled brakes...open bleeder, pedal pushes to floor as fluid shoots out.

with the jeep off we have very solid pressure. the second you turn the jeep on the pressure is lost.

i just crawled some rocks in my backyard with the jeep in 4 low and coming down the rocks it was nearly impossible to stop without leg pressing the pedal pretty hard, so yeah gonna have to fix this guy haha

[ct67_72]

Does it have ABS?

[ct67_72]

Hotline Archive With OEM Direct diagrams, components, TSBs, and R&R procedures
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Number: 123314
Vehicle Application: 1996 Cherokee 4.0 1994 Grand Cherokee 5.2
1993 Grand Cherokee 4.0 1995 Grand Cherokee 5.2
1994 Grand Cherokee 4.0 1996 Grand Cherokee 5.2
1995 Grand Cherokee 4.0 1997 Grand Cherokee 5.2
1996 Grand Cherokee 4.0 1998 Grand Cherokee 5.2

Customer Concern: Soft brake pedal after a master cylinder and brake booster replacement.
Average Reported Mileage: 170498
Tests/Procedures: 1. Try running the "Bleed Brakes" function using a compatible scan tool. If the Hydraulic Control Unit (HCU) went dry during the master cylinder replacement, there will be air in the HCU that will not come out until the procedure is run on the scan tool. After running this procedure, it will be necessary to bleed the brakes conventionally afterwards as the air will get pumped out to the base brakes system. Perform this function a few times until no more air is present.
Author: Greg Montero
Technician Biography
Greg Montero Greg began his automotive career in 1990. His experience includes working as a technician at an independent repair shop as well as some GM, Jeep/Eagle dealership experience. He also has Service Manager experience at an independent repair shop. He is on the St.Paul Technical College advisory board, and is involved the AASP MN, serving on the Training and Education committee. He is certified ASE Master and L1 and has recently completed his AAM (Accredited Automotive Manager) certificate from the Automotive Management Institute. Greg volunteers on the audio-tech team at his church and enjoys spending time with his wife and two sons.

Potential Causes With OEM Direct diagrams, components, TSBs, and R&R procedures

AIR — Air in the system.


Confirmed Fix Summary

[ct67_72]

I keep finding the same reported fix on direct-hit/identifix. Looks like if you get air in the brake control unit you have to run the bleed procedure with a scan tool. Seems to be a pretty common thing.
You still have to make sure and adjust the shoes first thing.

[HeavyMetal]

Does it have ABS?

had a d35 with ABS stock. cut the wires and swapped in something else non ABS.

I keep finding the same reported fix on direct-hit/identifix. Looks like if you get air in the brake control unit you have to run the bleed procedure with a scan tool. Seems to be a pretty common thing.
You still have to make sure and adjust the shoes first thing.

interesting. i will be adjusting the shoes ASAP in the meantime. guess i need to find the right scan tool now

[ct67_72]

Mine might do it, but it looks like as long as you have the BCU than it needs to be bled that way. You may end up having to bypass it.
Definitely adjust the brakes first, as it will do what you say, but you may end up with the BCU issue

[CumminsJeep]

I have had to do this procedure a few times on not only chryslers but fords and chevys as well. It happens a lot when you replace brake lines or the actual unit itself. the problem is finding someone with a MODIS or comparable scan tool. I have a MODIS at work and I know Bryan has one.

[HeavyMetal]

I have had to do this procedure a few times on not only chryslers but fords and chevys as well. It happens a lot when you replace brake lines or the actual unit itself. the problem is finding someone with a MODIS or comparable scan tool. I have a MODIS at work and I know Bryan has one.

lets say i left a day early for RCQ and stopped in. reasonable? its right on the way obviously and itd give me a break in my drive.

only thing is i definitely 150% need the jeep for the race so it cant become an ordeal

doesnt sound like something you could bring here when you are here.

this is assuming i need to do it at all

[ct67_72]

I will look and see if my genisis will do it.