Gents,
Got a problem with my wife's grandmother's farm truck... '93 C2500. Master cylinder was replaced on it two months ago. I had to drive the truck today and it damn near scared me to death the first time I hit the pedal. It goes soft until about an inch from the floor then its still not 100%. When I got back I bled the brakes, ran a whole quart bottle thru it, still as mushy. Pedal will firm up with the truck off and the pedal is 'harder' when bleeding the rears. Anyways, went and got another master cylinder, bench bled it , and put it on, bled the truck with 2 whole quarts, and still nothing. Brakes are in fine shape, new rotors and pads back in the fall, rears look fine as well. No calipers or wheels cylinders are leaking either.
Just thought to check the rubber lines but I don't think that a bulging or swelling hose would make the pedal this soft. If the vac booster was bad wouldn't the truck act like it had manual brakes and a hard pedal? Also when you depress the pedal (with the lid off the resivoir) should their be a 3" gyser like stream shooting straight up out of the rear half of the NEW master cylinder?
I don't like the thought of her driving at all but if she's gotta do it I rather her be safe, and others on the road as well.
Any help would be greatly appreciated as always.
TIA,
Got a problem with my wife's grandmother's farm truck... '93 C2500. Master cylinder was replaced on it two months ago. I had to drive the truck today and it damn near scared me to death the first time I hit the pedal. It goes soft until about an inch from the floor then its still not 100%. When I got back I bled the brakes, ran a whole quart bottle thru it, still as mushy. Pedal will firm up with the truck off and the pedal is 'harder' when bleeding the rears. Anyways, went and got another master cylinder, bench bled it , and put it on, bled the truck with 2 whole quarts, and still nothing. Brakes are in fine shape, new rotors and pads back in the fall, rears look fine as well. No calipers or wheels cylinders are leaking either.
Just thought to check the rubber lines but I don't think that a bulging or swelling hose would make the pedal this soft. If the vac booster was bad wouldn't the truck act like it had manual brakes and a hard pedal? Also when you depress the pedal (with the lid off the resivoir) should their be a 3" gyser like stream shooting straight up out of the rear half of the NEW master cylinder?
I don't like the thought of her driving at all but if she's gotta do it I rather her be safe, and others on the road as well.
Any help would be greatly appreciated as always.
TIA,