abs and spring problem

[trekster]

Hi guys,

I have a weird problem with my 90 cherokee(limited, 4.0, auto, 190thou). Actually two problems, they may be related.
First prob, when I start out forward or reverse, I get a thunk sound. It looks to me like the rear springs so soft that they are allowing the axle to twist so far that the shocks are hitting the axle. Is this spring wrap?
Second prob, when coming to a complete stop, the ABS is letting go of the front wheels at the last two feet or so and the rear brakes are not stopping very good. This started when new rear brake shoes were installed. So, when you stop, the last couple of feet feels like the jeep doesn't have brakes but then it stops. If you pull the Ebrake while stopping, the front wheels do not left go, so it stops fine. Maybe this isn't the best explaination but I hope someone can help me.

Thanks

 

[XJNick]

Although I don't have ABS, it is my understanding that ABS should not engage during normal braking, only when it detects the wheels are spinning at different speeds. If this is the case, I'd check that all the wheel speed sensors are functioning properly. By using the Parking brake in the rear, you are slowing the rear wheels down at a quicker rate than the front, causing the ABS to apply more power to the front wheels.

Once you've determined that the ABS is functioning properly, I'd go back and check/adjust/replace the brake pads,shoes,etc. if the problem still persists.

-Nick :!:

 

[trekster]

I talked to a mechanic and he drove it around. He thinks the front wheels are doing all the work and the sensor thinks the front is going to lock up so they "let go" and the rear shoes have not worn in yet. His suggestion is to drive it and see if the rear shoes wear in. I'm still not sure what to do. Thanks

 

[XJNick]

When I installed new brake shoes, they didn't take very long to wear in. The rear brakes on my cherokee have never stopped as well as the front ones, but I can definately feel them working.

You might try bleeding the brake system again. You MUST bleed all four brakes. Normally, you bleed in the following order:

right rear
left rear
right front
left front

Also, check that the star adjusters are functioning, that the brake lines aren't crimped or leaking, be sure that no axle fluid is leaking into the brakes, and think about possibly replacing or "turning" the drums. :mrgreen:

-Nick :!: