ABS Unit
Thread Starter
Safety Car
Joined: Mar 2017
Posts: 4,189
Likes: 1,312
From: LeClaire Iowa
ABS Unit
I see many posts about the ABS unit. I read the post where someone took it apart and showed how the screen filters were all clogged up. My 96 was owned by an elderly man who drove it very easy and I would bet money he never activated the ABS for the first 27k miles until I bought it. I know it cycles for a couple of seconds every time you get to 3 MPH. I don't know if this cycle actually moves any fluid. Here is my question: It appears that the screens and unit clog up because they never get any flow to flush the unit. I have said before I think GM should have installed a flush switch to cycle fluid through the unit for 10 minutes (guess) before flushing the fluid. Does flushing the fluid in the regular way move any fluid through the screens and unit? Without the Tech2 unit that can cycle it should you go on to a gravel lot and cycle the ABS unit naturally before regular flushing? Dan
Drifting
Joined: Feb 2016
Posts: 1,384
Likes: 339
From: Simi Valley CA
I had a problem with a stopped up unit in my 89. Fluid would not flow out of my rear calipers no matter what I did, both left and right. Traditional bleed, gravity, vacuum, pressure, etc. I took out the original ABS and replaced it with a wrecking yard one from a low mile car that was wrapped around a pole. It bled fine after that. The ABS unit is in the middle of the lines. So if you bleed the brakes and fluid moves, it is going through that unit and definitely flushing it. If it is gummed up, fluid will not bleed out of your calipers. There is one line coming out of the ABS for both rears and there are 2 single lines coming out 1 for each front.
