2002 Silverado 1500 5.3L
Equipped with VSES/ABS

OK so longs story short. I replaced ALL the brake lines in the truck as well as the front two hoses to the calipers. New calipers/rotors/pads on the rear. I used my scan tool to bleed the VSES and ABS system then did a manual bleed on all four tires. RR -> RL -> FR -> FL. I've done this at least 10 times now. When I start the truck the brake pedal is immediately spongy, While pumping and bleeding the brakes the master cylinder seems to be building good pressure and I am no longer getting any air from the lines. I am not seeing any leaks at any of the flares. 99.9% positive that the system is closed up nicely.

Local guy is saying that the master cylinder may be going bad. Is this a possibility? Am I bleeding the brakes incorrectly?


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were they new new? Or reman? Reputable brand? (ideally AC Delco)
I've seen calipers be leaky right out of the box. Problem solved with new Delco parts.

definitely a possibility. Those seals wear out. Especially after 21 years.

 

Remanufactured car quest calipers. Nots seeing any drips from the calipers. Definitely would have with as many times I've bled the system.

Ordered an AC Delco Master Cylinder should be here tomorrow.