Help needed, from any mechanics

[sdt354]

I've got a situation driving me crazy. Short version, I opened up the brake system on a 2000 GMC pick up. Air got into the ABS pump and I've struggled trying to get a pedal. I've bled multiple bottle of brake fluid through it until no air was coming out of the bleeders.I've bled countless systems in the past. I had a young guy with the Snap-on ABS code reader try to activate the ABS system to get the rest of the air out. He said it wouldn't work until I replace a wheel sensor. Talked to brake shop mechanics and they made a sad face as soon as I said ABS. I did the skid method of trying to activate the system. I was told to run the truck to 55 mph on jack stands, I'm not doing that. This thing makes the Vmax clutch bleed look like a piece of cake. Hmmm, I haven't tried reverse bleeding yet. I was wondering if a pressurized system would do the trick, too. Any help would be appreciated greatly.
Steve-o

 

[eggohead]

Hang in there.. I haven't ever done too much with ABS, and I hate working on brakes...

 

[blaxmax]

Have you tried a mity-vac?

 

[blaxmax]

It will only cost me $5.95 to mail mine to you.

 

[Fire-medic]

Yep I would try the reverse-bleed.

Edit 3/4/16: Since forestdaledave said the GM tech bulletin said, "no reverse-bleeding," don't. I am guessing that they consider the possibility of pushing some piece of crud into a valve to keep the ABS from operating properly.

 

[Traumahawk]

I think it needs to be pressure bled.

Look at this.

http://www.harborfreight.com/brake-fluid-bleeder-92924.html

 

[sdt354]

It will only cost me $5.95 to mail mine to you.[/QUOT
Much appreciated, but I have one. I have a brake vac bleeder system,but the issue seems to be the Valving Iinside the ABS pump. Code is showing a left front sensor bad.

 

[sdt354]

I think it needs to be pressure bled.

Look at this.

http://www.harborfreight.com/brake-fluid-bleeder-92924.html

I've got one of those but it is really a vac unit using compressed air.

 

[blaxmax]

It will only cost me $5.95 to mail mine to you.[/QUOT
Much appreciated, but I have one. I have a brake vac bleeder system,but the issue seems to be the Val I ginside the ABS pumIt is showing a left front sensor bad.

Don't you hate computers I know I do.
Trying to get even Steve-o.
I will.

 

[Dorney]

I've got a situation driving me crazy. Short version, I opened up the brake system on a 2000 GMC pick up. Air got into the ABS pump and I've struggled trying to get a pedal. I've bled multiple bottle of brake fluid through it until no air was coming out of the bleeders.I've bled countless systems in the past. I had a young guy with the Snap-on ABS code reader try to activate the ABS system to get the rest of the air out. He said it wouldn't work until I replace a wheel sensor. Talked to brake shop mechanics and they made a sad face as soon as I said ABS. I did the skid method of trying to activate the system. I was told to run the truck to 55 mph on jack stands, I'm not doing that. This thing makes the Vmax clutch bleed look like a piece of cake. Hmmm, I haven't tried reverse bleeding yet. I was wondering if a pressurized system would do the trick, too. Any help would be appreciated greatly.
Steve-o

Steve is the ABS light on ? if so the pump won't run. If not did you say you did run 1 front tire on gravel & hit the brakes. You don't have to be going that fast.

Dave

 

[sdt354]

Steve is the ABS light on ? if so the pump won't run. If not did you say you did run 1 front tire on gravel & hit the brakes. You don't have to be going that fast.

Dave

The light is on Dave. So I take it skidding isn't going to help? What I'd love to know, and it appears to be a proprietary secret, is how to hot wire that dam ABS pump to circulate the air. Thank for responding guys.

 

[jfeagins]

Maybe something in this old thread on a silverado forum will help?

http://www.silveradosierra.com/brakes/bleeding-the-brakes-but-wont-bleed-t11801.html

 

[sdt354]

Maybe something in this old thread on a silverado forum will help?

http://www.silveradosierra.com/brakes/bleeding-the-brakes-but-wont-bleed-t11801.html

That's some great info Jay. Just getting the pump to run should do it. It's amazing how little info there is on this. Thanks much. I owe you a bear at Thunder for sure.
Steve

 

[jfeagins]

That's some great info Jay. Just getting the pump to run should do it. It's amazing how little info there is on this. Thanks much. I owe you a bear at Thunder for sure.
Steve

Not sure how hard you party, but I prefer to party as far away from any bears as I can get. :biglaugh:

Maybe you can just shake my hand, or similar, at the Maggie Valley rally instead? :ummm: :biglaugh:

 

[forestdaledave]

Steve, at GM school we were told never to reverse bleed ABS systems. To the point of never collapsing the piston back into caliper housing without first opening bleeder screw when installing new pads. Many people do it but there is a chance of that one time of getting contamination in the control unit. If I remember correctly the truck needs to be going at least 15 mph for the ABS to be activated in a panic brake event. If the ABS light is on that needs to be attended to first. System will not work with light on. trying to hot wire the pump could result in frying the electronic module. They can be bleed conventionally by pressure bleeding and should be done that way. It does take a lot of fluid.

 

[Dorney]

The light is on Dave. So I take it skidding isn't going to help? What I'd love to know, and it appears to be a proprietary secret, is how to hot wire that dam ABS pump to circulate the air. Thank for responding guys.

Steve if you take it to advanced auto & have it scanned they can tell you what you need to fix the ABS. At that point you can do the brake check in gravel to get the air out.

Dave

 

[sdt354]

Not sure how hard you party, but I prefer to party as far away from any bears as I can get. :biglaugh:

Maybe you can just shake my hand, or similar, at the Maggie Valley rally instead? :ummm: :biglaugh:

ok, we'll have a polar beer....

 

[sdt354]

Thanks all. The latest software & scan tool can clear an ABS fault code then make the ABS system cycle. I had it done, then deactivated the system by pulling the fuse, and it was worth the $50. Then I took it home and bled the rest of the air out, normally and put the fuse back in for a test ride. Nice pedal and brake operation. Lesson learned.
Steve

 

[Traumahawk]

Thanks all. The latest software & scan tool can clear an ABS fault code then make the ABS system cycle. I had it done, then deactivated the system by pulling the fuse, and it was worth the $50. Then I took it home and bled the rest of the air out, normally and put the fuse back in for a test ride. Nice pedal and brake operation. Lesson learned.
Steve

Thanks for posting what it took to fix it. That way we can all learn something from this.

 

[Dorney]

Thanks all. The latest software & scan tool can clear an ABS fault code then make the ABS system cycle. I had it done, then deactivated the system by pulling the fuse, and it was worth the $50. Then I took it home and bled the rest of the air out, normally and put the fuse back in for a test ride. Nice pedal and brake operation. Lesson learned.
Steve

Steve why was the ABS light on in the first place ? :ummm:

Dave