Mechanic

[Wildman318]

Our company owns several 1 ton 3500 General Motors dump trucks with ABS on them. All the brake lines were rotted and were fully replaced. I tried the old style conventional brake bleeding on it and got no from brake pedal. What are we doing wrong??? Signed: the wildman 318

[Jsdirt]

Probably some air in the ABS unit - happens occasionally. Might have to find a dirt, or sandy road, and do a couple ABS stops in it, then try again.

 

Of course if you've got a bi-directional scan tool, you can activate the ABS while bleeding.

[Colossus]

In some cases (not sure with GM) you have to use a Tech-II to activate the ABS unit to purge things. 

[sdeeter19555]

In some cases (not sure with GM) you have to use a Tech-II to activate the ABS unit to purge things. 

This is how I understand my 2012 needs the brakes bled...I need the brake system flushed, and will be taking it to the garage next week so they can cycle the ABS.

Sent from my SAMSUNG-SM-G900A using Tapatalk

[Jsdirt]

4 hours ago, Colossus said:

In some cases (not sure with GM) you have to use a Tech-II to activate the ABS unit to purge things. 

Any bi-directional scan tool can do this - doesn't have to be a Tech 2.

[Wildman318]

On October 12, 2017 at 1:56 PM, Jsdirt said:

Probably some air in the ABS unit - happens occasionally. Might have to find a dirt, or sandy road, and do a couple ABS stops in it, then try again.

 

Of course if you've got a bi-directional scan tool, you can activate the ABS while bleeding.

 

[Wildman318]

This may be true, but I cannot use my Tech 2 scanner to "auto bleed" for the ABS system because I cannot erase a code c0550... I need to erase this vide first. Wildman318