97 cavalier with abs/traction control problems.. help!

[busa4]

my vehicle is mainly braking with the rear drum brakes. i have bled and bled the brakes, master cylinder, and abs unit and have achieved no change. my abs light goes off just after the vehicle starts and there are no fault codes. my back brakes are doing all of the braking and they lock up all the time which tells me my abs is doing nothing. is the abs unit suppossed to cycle when you first start moving your vehicle as a self test?. if so, mine does not. i dont want to throw parts at it so is there anyway i can test wires to see if the problem is the abs hydraulic unit or the abs control unit? any professional (GM tech) help is appreciated. i dont mean to offend anyone but this is more of an advanced problem that only a gm tech will be able to answer or help me on. i am also a tech but i work on porsche's and i dont know the GM abs system. thanks for your help.

[Cavalier2000]

I'm lost, your not using front brakes at all, if this it true then yea your abs will mess up and so will your traction control. Maybe i just didn't read right

[Lances133]

....huh? what happened to your front brakes?

[busa4]

the abs hydraulic unit is part of the master cylinder. all or most of the brake pressure is going to my rear brakes and locking them up when there cold. when they lock up there is no cycling of the abs. i have front brakes but there is limited brake pressure to them. i want to know testing procedures for the hydraulic unit or the abs control unit. if i knew how this particular abs system worked i could figure it out but i dont have a wiring diagram or a function diagram to figure it out.

[busa4]

anyone with help/advice?

[busa4]

does anyone have this system? its the delco abs VI system. if you have it let me know if your abs system does a self test on cold start at 5 mph. i am trying to figure out if my abs hydraulic unit or my abs control unit has failed.

[abs-less-cavalier]

ok...so one day i'm driving around with my buddies and i come to a red light, and i put my brakes on.. (no wait let me correct that!) i put the brake pedal down, and nothing !!! but then the brakes start to grab and let go and grab and let go just as if the abs was skipping.. so i didn't look much more into it and unhooked the two abs sensors under the hood . eversince i did that the brakes have been working out just fine, only i don't have abs.... and thats cool with me. so hopefuly my experience helps you figure it all out.

CHEERS

[busa4]

that is what abs is supposed to do. why did you deactivate it? my problem was air in my brake system which was resolved by a complete system bleed.

[abs-less-cavalier]

nah, this wasn't a normal abs feeling...i could be leaveing a parking lot, and going about 10km/h and trying to stop, the brakes would miss and then grab really hard about 1 foot later. maybe all abs do that, but i haven't owned enuff abs equiped cars to really know, but the cav is fine with the abs gone, jsut suits my primative driving sett up.

if anyone thinks i'm gonna die soon if i don't hook my abs back up let me know, if its that big of a deal i will keep the abs........and change my screen name to something more appropriate.

-paul

[Derk_eliso]

only thing abs is, are a system for keeping your brakes from locking up... so like, as long as you pump the brakes you shouldn't have a problem? Henry Ford didn't...did he? lol

Anti-lock brake system....right?

[abs-less-cavalier]

true... i stand defeated....by henry ford of all people!

i'd rather push a chev, than drive a ford!

-p

[vintweed]

I had this same problem. It's been 3 years and many, many weekends later trying to figure it out. Never have, and I've come to the conclusion I never will. I've put on over 250,000 kms so far. No ABS is fine with me.One thing though, once in awhile the rear passenger side wheel will grab and lock while the others work normally. This only happens in snow or rain. (yah, keeps you on your toes) But I just changed the wheel sensor again, and so far so good.