Bought the truck in SC and drove it here to middle GA. Brakes died just before parking it at my house. It sat for about 5 months until I could begin to work on it. The brake system was dry when I started the work and unfortunately the pedal had been pumped that way. One of the front hard lines and the rear hard line both were rotted through and I replaced them (see
http://www.gmt400.com/forum/showthread.php?17339-biy-brake-lines). Then, when I went to bleed them one of the wheel cylinder bleeder screws was rotted away. Replaced the wheel cylinders and the calipers. Also put in a new master cylinder for good measure. Bled the brakes using a vacuum system and then again with speedbleeders.
Ok after the novel...
I have great pedal pressure until I start the motor then the pedal goes to mush. The brake warning light is on and the pedal is still mush even with the power plug undone on the abs module. I have good vacuum at the booster.
Is this an ABS bleed problem? Been all over the net in the last few hours and it looks like the only way to bleed the ABS module, short of buying a $500ish tech 2 scan tool, is to take it to go to the dealer.
Any other ideas?