Ok looking for info on the ABS controller on my 94 Z28. My rear brakes are not working and the mechanic has said they are not getting fluid from the master cylinder, that the ABS controller is not working. 3 years ago I had an engine install done and the mechanic had issues with the brakes. Neither the brake light or ABS lights are on but I have known for some time that there are issues with the brakes. I had the front worked on and that's when this new mechanic found he problem and identified the ABS controller as the problem. My question is what would cause it to not work because it did work prior to the engine install? And why aren't either of those lights on to indicate a problem?
How difficult is it to change that controller? Anyone have experience with this?
Thanks!

 

the lights may have been taken out so they would not light up, system could be disabled. check all fuses. check plugs to the abs unit to see if there plugged in. there is a proportioning valve that will shut brakes off if theres a leak. used to be front or rear, not sure now. may be one side or the other

 

Have you tried getting your ABS system scanned? I am not sure you would see a dash light for all ABS codes...

 

Any good internet sites that could give me more info about this? Is it a PITA to change? Mechanic quoted me $400 and another $200 to replace the master cylinder. Said the brake fluid looks like 'chocolate milk'..

 

I would check to see if your caliper slides are working smoothly and that the pistons are not rusted & seizing, this could cause the ABS Motor pack to fail, which happened on my old 95 3.4L. The motor pack replacement is easy by the way. You may have other issues though. Have you tried simple things like flushing the brake fluid? How long/many miles ago was it last changed?

 

I have owned the car for 4 years and have not flushed the brake fluid. Where is the motor pack located? I've seen the part on ebay for about $40 and if its easy I would just do it myself.

 

But how many miles in that 4 yrs? I would probably start off flushing your fluid, you may make some discoveries in that process. The motor pack on my '95 3.4L was located on the driver-side frame rail as I recall, a rectangular black plastic assembly. I found my motor pack was bad from an ABS scan and the resulting analysis a shop provided me.

These days Advance Auto have a scanner that will do the ABS system too, not sure if it supports back to '94, however... Might have to visit a shop for that.

 

My free app "Scan9495" can scan your ABS and SIR also. It even has a few ABS actuators, but not as much as a Tech 2. All you need is an ALDL cable.
http://www.mediafire.com/?0elo4c935uc5s#gonkz3785ph7o

 

I had this problem with my 94 Z28 last year, the rear brakes did not work, a local garage flushed the brake system several times and the rear brakes still did not work, I took it to the Chevy dealer and they used the computers to check the settings and said everything is correct. Then they flushed the brakes several times especially the rear many times and then they started to work.

 

I've driven this car 60,000 miles in the 3 years since the engine install. The brakes were troubling the mechanic when he was finishing up. Thanks for all the great info think I will start with having the system scanned and go from there.