02-09-10, 11:47 PM
I have a 68 deville that I did a front disk brake conversion from a 69 caddy. I purchased a refurbished master cylinder and installed the system. Initially the passenger side soft line was clogged and I blew it out and then bled the brakes....At first the brakes felt pretty good then it started going down to the floor and feeling hard to stop and the brake light is coming on....If anybody has any input it would be gratefully appreciated....
02-10-10, 12:00 PM
Only 3 things: There's air in the system somewhere (bleed everything, starting at the wheel cylinder furthest from the master cylinder - RR ?), the rebuilt master cylinder is faulty, or you have a leaking wheel cylinder/caliper puck seal.
On that old of a car, I would NEVER trust the rubber hoses. Blowing one out is not a repair. Pull the rear wheels and drums and lift up on each rubber boot on the wheel cylinders. If moisture (brake fluid) is present, you need to replace both rear wheel cylinders. That would account for the soft pedal also. If it were mine, I would replace all 3 rubber hoses. 2 front to each caliper and one at the rear axle. The red light comes on when a braking imbalance is sensed front to rear. Most times once the entire system is bled, the light will go out. If it remains on, then the proportioning valve below the master needs a line cracked open then quickly tightened while depressing the pedal to center the check ball within it.