I might KILL it.

[Dammann35]

I know know some of you guys have read the other thread I made about the low brake pedal but I'm out of options, so if you have any ideas or input PLEASE HELP!!!!

So it all started 2 months ago. I parked my truck inside at work and let it warm up cause it was in the teens outside. As I go and start my truck after sitting inside for 8 hours my brake light and ABS light come are on the dash. I scanned the codes and go a C0040 and C0055 which is rear speed sensor and right wheel speed sensor. I drove it home and on the way I noticed that I didn't have abs and I kept my scanner plug in and was reading the data. I then looked under my engine codes and I had a lost communication of EBCM. I replaced the EBCM and after replacing it my abs light was acting weird, It was on but when I stepped on the brake it would go out and I would release the brake and it would come back on? The codes (C0040 and C0055 were still on) so I switched the VSS and replaced the right wheel hub. After that my lights on the dash went out, but I have a low brake pedal and so I bled the brakes and it got a little better. When the vehicle was off the pedal would get hard but then real slowly go down. Thinking it was the master I replaced it and bled it for hours and even let it gravity bleed and then rebleeded it and still have the same result. I'm tired of putting money into this problem and working at a GM dealer the techs never seen a problem like this. So idk if any of you have but hopefully you guys/girls (JorDanee Keys) can help me.

[v7guy]

It sounds a lot like air is in the system, if you replaced the brake control module (I don't remember if the electronics can be separated from the ABS valves) there is likely air introduced into the lines when from when the valves cycle... in this case it would push air into the system as the ABS valves pulse or cycle during a check. A tech 2 can manually open the valves so the ABS block is bled, otherwise you need a decent empty parking lot to engage ABS and bleed the system that way... not that I would advocate doing something like that... I've experienced this exact scenario with some older GM products.

If that's not it, it could also be a small leak somewhere in the system, does the brake fluid reservoir stay full?

Outside of that, I got nothin

[Dammann35]

I used the tech 2 and did an automated bleed and still had the same problem. Since I have off tomorrow I'm just gonna bottle bleed it and see what happens.

[SomeOffPave]

I used the tech 2 and did an automated bleed and still had the same problem.

I am old school and just plain old so I know about using the brake pedal inside the truck to bleed brakes, I know about pressure bleeding, and I know about vaccum bleeding but I have NO idea what "automated bleed" is. Please explain.

[TBYODA]

I used the tech 2 and did an automated bleed and still had the same problem.

I am old school and just plain old so I know about using the brake pedal inside the truck to bleed brakes, I know about pressure bleeding, and I know about vaccum bleeding but I have NO idea what "automated bleed" is. Please explain.

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