SasquatchOnDeck
OBS Enthusiast
a couple weeks ago, i backed up a hill a steep hill, parked (with parking brake), dropped my tailgate, and rolled a considerable log into the back of my 89 K3500. when i started it up an released the Peebrake, the brake light on the dash didnt go out... i shrugged, went to put the truck in gear, and the brake pedal went to the floor. It went almost all the way before there was any resistance. If i let it idle in drive, it would take 10 feet or so to stop from less than 10mph.
I've since replaced the vacuum booster and master cylinder, which was bench bled. I've bled the brakes at each wheel. so. many. times. the pedal is still spongy, and goes to the floor to stop the truck. i know OBS brakes suck, but neither of mine ever sucked this bad. the brake light is still on the dash, usually only when i press the pedal. there are no leaks, and the rubber flex lines are questionably old (ive had the truck a year) but don't visibly swell when brakes are pressed.
Any ideas here? Based on my reading, tomorrow im gonna get it up around 35 on gravel and lock them up a few times (it will still lock the brakes on pavement if that helps diagnose an ABS problem... lol), from what i've heard that's the poor man's ABS bleed, if you can even do it from OBD1.
Also, i have an ALDL cable and Tunerpro RT, but don't really know what im doing with it, if there's anything brake related in the data stream, please tell me where to look and i'll throw that in here ASAP.
I've since replaced the vacuum booster and master cylinder, which was bench bled. I've bled the brakes at each wheel. so. many. times. the pedal is still spongy, and goes to the floor to stop the truck. i know OBS brakes suck, but neither of mine ever sucked this bad. the brake light is still on the dash, usually only when i press the pedal. there are no leaks, and the rubber flex lines are questionably old (ive had the truck a year) but don't visibly swell when brakes are pressed.
Any ideas here? Based on my reading, tomorrow im gonna get it up around 35 on gravel and lock them up a few times (it will still lock the brakes on pavement if that helps diagnose an ABS problem... lol), from what i've heard that's the poor man's ABS bleed, if you can even do it from OBD1.
Also, i have an ALDL cable and Tunerpro RT, but don't really know what im doing with it, if there's anything brake related in the data stream, please tell me where to look and i'll throw that in here ASAP.