Bleeding ABS Module

[Shaun Kiss]

Currently doing some brake work on a 1996 Chevrolet 1500 6.5 litre turbo diesel. The brake system is a front-rear split. I was helping my older brother replace the brake lines going to the rear brakes. We replaced the whole line connecting from the ABS module to the rear wheels. The difficult part is bleeding it, in order for us to bleed all the air out of the system (and there is a ton of it), we have to start at the ABS module before we can go to the rear wheels or otherwise it will be a waste. My question is: How do you bleed the ABS module? Do you need a scan tool to do it? I know theres two bleeder screws on the side of the module but when we loosened them, very little brake fluid came out. The pedal still sinks to the floor. So what’s the solution for me?

Topic

[george gonzalez]

Just bleed it as normal. The ABS system, when it’s idle, does not affect the brake system. There is still the same fluid path, just a little bit longer and with a bit more volume. To bleed the back side of the ABS system you sometimes have to jump through a few hoops. I would first get the basic brake system bled first, that helps morale.

[Bryan]

You would need the tech II or after you bleed go out and do a few stops to engage the ABS and then rebleed. I am not sure this would get all of the old fluid out though. Best bet if you want a full purge use a tech II. The masters been bench bled? Ive also heard of getting it off the ground with wheels off and bleeding the module while running…not too sure about that tho.

[Kevin Criswell]

You will not need a tech II for that particular model, it is only rear wheel abs and the module is what is commonly called a pass-through.

Here is the OEM instructions

Attachments:

• blledingc1500.pdf

[Shaun Kiss]

I always forget the finer details. The vehicle is 4WD with ABS in the front (not 100% sure if the back does but I think it will if I go back and check once more). We have no pressure/working brakes in the rear brakes but when we apply the pedal and check the front we do. I was hoping to not have to use a scan tool but I’m afraid that its the only way I’m going to get the job done. In the meantime I’m going to manual bleed the rear brakes and then get the scan tool on the go.

Thank you all for replying on the this topic.

[Kevin Criswell]

Here is the bleed procedure for the 4WABS unit

On the 4 wheel unit you do need a scan tool to run the function test if air got in it.

Attachments:

• 4wheelABSbleed.pdf

[EricTheCarGuy]

+1 on needing a scan tool for that model. Once you get that sorted if you could report back and let us know how you got it solved we’d appreciate it very much.

[Author]

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