2005 Chevrolet Express Front brake problems

SHAWNYBOY20

MEMBER
2005 CHEVROLET EXPRESS

Hi I have a 2005 chevy express van I've been trying to figure this out for awhile but I got all brand new brake lines front and back so started bleeding the brakes and couldn't get any fluid to either front sides only getting fluid to the back I can't get any fluid to the front also have brand new brakes calipers rotors all the way around I just can't figure it out no fluid comes out of front I've bled the master cylinder still nothing out of lines any help thank you

1 Reply

CARADIODOC

MECHANIC
33,871 POSTS

GM uses a master cylinder with a valve inside to block two ports when there's unequal pressures, as in a leak, on their front-wheel-drive cars. It sounds like they might be doing something similar on your vehicle. The clue is once the rear is bled, you'll have a solid, high brake pedal even with the front bleeder screws open. If that is the case, use compressed air and a rubber-tipped air nozzle to give a quick, very short burst of air to one of the open front bleeder screws, then let both front calipers gravity-bleed.

That valve will not trip if you never push the brake pedal more than halfway to the floor. That should never be done either on any master cylinder that's more than about a year old because the internal lip seals can be torn on the crud that accumulates in the lower halves of the bores where the pistons don't normally travel.