needafix

I'm not sure if this should be a reply on this thread or a new topic, let me know if it's out of place. This my first post. Thanks 85077522 - ACDelco GM Genuine Parts Brake Master Cylinders. Anyone else had to replace this brake master cylinder yet. I didn't do any brake work, it looks like new parts and I've had the truck for about 4k miles. When it started to throw codes I did the calibrations with a bidirectional scanner and got the codes to clear but they came back so i did the routine; base bleed, automated bleed and final base bleed. All that with Bosch ES16-32N fluid (please look it up). That seemed to fix it but 100ish miles later it failed again so I ran the same process but with a pressure bleeder this time and got the same results, fixed for 100ish miles. The original fluid looked bad and I thought I got most of it out. The codes; P25A2, C05B0-00, C2A1B. I can get them to clear but not for long. The C05B0 indicates a leak in the front circuit (which is bone dry) so I'm thinking of doing the bleed process on that front again today and I don't know if that's taboo to just do the front but at this point it seems like it's worth the try anyway. The new master cylinder/module unit is supposed to get here today. But now I'm pretty much convinced this install is over my head. I've called several shops and some mobile guys that I know but this thing is like radio active material scary wise. I did get 2 local shops say they should be able to do it, one says he has the SPS2 programing capability. And with the battery disconnected is there supposed to be pedal resistance, mine is to the floor, then if I pump it I can get some resistance.