problems with ABS

[chico71]

have a 94 grand Cherokee and when i apply the brakes and is wet or when there is snow the pedal kicks back and the brakes lock i don't have an idea on what's going on can somebody help

[dksob81]

well if u hit the brakes hard, the pedla will pulsate when the wheels begin to lock-up, this is b/c the ABS is kicking in trying to keep the brakes from locking up.

but if it is locking up still and u are not applying alot of pressure to the pedal, that could be a problem

[chico71]

last year i did not use the truck in the snow because if i touched the brakes it lock and it started to slide like if i did not apply the brakes and had a very loud sound from the front like something was loose but i check everything in the brakes and did not find anything loose any ideas

[Cam7]

Is your ABS Light on? If It is is it on when you are sitting still or does it come on when you are moving? Does the noise happen on dry conditions? Onthe Pedal pulsating it is the way ABS system works like pumping your brakes on non ABS vechiles. ABS will still go in to a slide just not as much as non ABS especially if you pump tthe brakes.

[dksob81]

do it sound like a rattle? if so check the ABD sensor, it is prolly loose, but the problm I have there is it would rattle all the time, but thats something to check,

I put a new Tranny in a friend 3000GT and he lost one of the bolts to the ABS Sensor so it is loose, and whenever u apply the brakes it rattles and the pedal pulsates. that just something to check, I doubt it is, but.....never know

[dksob81]

also, if the brakes are locking up all the time, then I would check the ABS Wheel Speed Sensors, they maybe dirty and telling the ABS Module that the vehicle is not moving and allowing the brakes to lock-up, if thats not it, then the ABS module (pump) is prolly bad.

[chico71]

The ABS light comes on some times usually after i start the car and it goes out when i drive for a wile only once it stayed on that was around 2 months.
I have not seen the light com back on for around 2 months but its still doing the same thing, when its dry it stops good the only thing is that i started to feel the pulsation now wen is dry. The noise that i hear i cant describe it but it sounds like air and at the same time a rattle i have never heard nothing like it, it sounds like the front of the car is going to fall apart. The only time i find the brakes locking is if it is wet, snow, or some leafs on the road i will check the sensors tomorrow to see if they are loose. thanks for all the help i hope this info will help me find the problem (are their sensors in all 4 wheels?)

[Cam7]

Sounds like it could be your Modulator . Its really hard to tell without a Scan Diagnostic.The noise you hear the Air Sound sounds like your Modulator breaking down or Brake Booster. Check the regular braking system in the front clapiers, pads and rotors. You will have to find some one with a Scan Tool with ABS Capabilty to Diagnostic your ABS problem you cant self read the ABS codes with out one. You might check the resistance value of your wheel sensors 800-1400 ohms. Check the regular braking first. and go from there.

[dksob81]

also try to clean the sensors and ring tone on the axle.