so i just replaced the master cylinder because the pedal slowly went to the floor, and after awhile lost brake fluid for the rear brakes, which causes the pedal to basically go to the floor and it only applys the rear brakes, which is wierd cause it has no bluid in the front half of the master cylinder. all the brake lines are brand new, except for the rubber lines on the front of the truck, when there is fluid in the master cylinder the pedal still isnt very firm and goes to the floor if pushed hard enough. the brake and abs light are on. is there a way to get a "code" off the obd 1 to figure out what tripped those lights? and why arent my brakes working? i havent touched the shoes/drums since i've owned the truck. but they seem to work fine. which is wierd.

 

I had to replace the cylinders in the rear drums, that cleared my problem.

 

Did you get all the air bled out after replacing the lines ?

 

got all the air out. gonna do wheel cylinders tommorrow.

 

pretty common to blow the seals out on the rear wheel cylinders. they are super cheep, im almost certain its an upgrade to buy the wheel cylinders from a 3500 chevy, i know thats what i used on my chevy but im pretty sure they did the same thing on that cummins project truck on the show "trucks!". maybe give it a quick search.