Mark_MS

My 2003 Silverado LT is my everyday ride with 215,00 miles.
I was coming home from work one night and 2 deer jumped out in front of me and slammed on the brakes to avoid them, they lived w/o injury.
Right afterwards my ABS and red brakelight came on, I didn't think too much about until I needed to make a turn and my brake pedal went right to the floor with no resistance.I had lost my e_brake about 3 months earlier.

I found a leak in one of the lines behind the drivers side wheel where the line transitions from metal to the hose going into the caliper.

Further inspection revealed that all the front brake lines in the front needed replacement which I did, with preformed ones. two of us installed them in about 4 hours

We went to bleed the system and could not get the bleeder valves to open due to corrosion, so we replaced all the calipers.

Bled the system used 2 quarts of fluid, going Right rear, left rear, right front and the driver front absolutely no air in system good resistance in the brake pedal. Until I started the truck up and then the brake pedal went right to the floor.

Checked all the lines again for leaks, bled the lines again to be sure.

Any thoughts as to why I have resistance when truck is off vs none when on???

Mark_MS

171 Views and no ideas??

burnhedge

I wish someone had an answer cause I have the same problem.

tech2

if the system has a proportioning valve; the valve will have to be opened with a special tool to allow fluid to pass to the rear calipers.


google search images gm proportioning valve tool. they cost under $20.


the system may need to be bled at the m/c if you let the reservoir go dry, then the abs pump and then the calipers. When all that is done you still may need to do a automated system bleed with a scan tool.

tech2

BTINE91

Is that supposed to be a picture of the gm tech 2 scanner. I can't open it