Hello, I'm Cam. Please include all the details about your issue so I can accurately advise you. I cannot see your vehicle so please be detailed.
Did you change just the black box on top or the whole assembly? If the whole assembly then you need to do an ABS automated bleed with a scan tool to bleed the air out of the system.
i had to take the entire unit off truck .then changed the module. put the unit back on and no brakes at all
Ok, so air got in, can you drive it at all, even enough to get to a place where you can do an abs stop to make it cycle the valves? If not then you need the scan tool to do it.
what do you mean an abs stop.my abs light is still on is this because of the brakes not being bled or could it be i may have got the wrong module, it was salvaged.
IT does need to be programmed to your vehicle so the stop is not an options.
but if it was not on, then driving and trying to lock them up on a road where it would just skid is what I was talking about
i can probably drive it ,but i have no pedal at all.
Ok then do not drive it.
You need a scan tool to do the ABS bleed.
It cycles the valves to release the trapped air.
is this scan tool is probably something only a gm mechanic would have ?
No any shop has them.
ok i guess i will try to locate a scan tool ,thanks
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is there any thing i should know after i get the tool
Bleed the brakes as best you can before, do the bleed then bleed the brakes again after.