Silverado Brake Bleed Question

xrmik · September 14, 2020

2000 silverado 4.8L. Brake lines rusted out. Vehicle sat for a few months with the lines cut from the abs pump. I lost all fluid. ABS fuse was pulled. Fast forward to the repair... I replaced lines and tried to bleed the traditional way and got nothing although I had pumped about a quart into the system.

My MC was corroded and old and I figured that was part of the problem so I replaced it before resorting to towing it into a shop.

Afterward I was able to bleed the brakes at all 4 corners with the 2 man method. Most of the air seemed to escape from furthest rear. I used another quart or so when bleeding. I then reinstalled the ABS fuse (no lights now on dash). Brakes seemed a little soft after doing it but I went on a gravel road and made some hard stops and it seemed to tighten it up afterward. I did not bleed the system again.

So my question:

Is it impossible that my brakes are bleed correctly as they stand now?

I ask because I read the warning about needing a scan tool to bleed the ABS to be able to get anything from the calipers at all. I am confused as it seems satisfactory now.

ClipperSkipper · September 15, 2020

Sounds as though you bled the brakes properly, and any remaining air usually works itself back to the BMC.

xrmik · September 15, 2020

Thanks for the reply. Im second guessing myself after reading all the posts about the abs module needing the scanner.

I also read about cycling the abs on a gravel road which i tried to do. However i am unclear exactly how the abs and truck should respond in such a case. The truck just came to a stop, no skidding... the pedal was softer than it was when i was normally stopping on pavement. Also no abs light came on like i thought it might if i activated the system.

Edited September 15, 2020 by xrmik

swathdiver · September 15, 2020

On 9/14/2020 at 4:24 PM, xrmik said:

2000 silverado 4.8L. Brake lines rusted out. Vehicle sat for a few months with the lines cut from the abs pump. I lost all fluid. ABS fuse was pulled. Fast forward to the repair... I replaced lines and tried to bleed the traditional way and got nothing although I had pumped about a quart into the system.

My MC was corroded and old and I figured that was part of the problem so I replaced it before resorting to towing it into a shop.

Afterward I was able to bleed the brakes at all 4 corners with the 2 man method. Most of the air seemed to escape from furthest rear. I used another quart or so when bleeding. I then reinstalled the ABS fuse (no lights now on dash). Brakes seemed a little soft after doing it but I went on a gravel road and made some hard stops and it seemed to tighten it up afterward. I did not bleed the system again.

So my question:

Is it impossible that my brakes are bleed correctly as they stand now?

I ask because I read the warning about needing a scan tool to bleed the ABS to be able to get anything from the calipers at all. I am confused as it seems satisfactory now.

You also have to bleed the ABS system and that is done with a Tech-2 or equivalent. Replacing all of my calipers and draining the old fluid out, I went through 6 quarts of brake fluid after doing the traditional and ABS bleeds.

xrmik · September 16, 2020

I bled it a second time, after doing the hard stops on gravel and the pedal seems great. In fact it a noticeable difference than how its been the last year or two with the rusted out lines and corroded master cylinder.

If there was still air in the pump, would it be immediately apparent by pedal feel?

Edited September 16, 2020 by xrmik