On some ABS systems, if you don’t crack open the bleeders prior to compressing the pistons back into the calipers it can reposition/damage solenoid valves in the ABS pump.
Tester
On some ABS systems, if you don't crack open the bleeders prior to compressing the pistons back into the calipers it can reposition/damage solenoid valves in the ABS pump.
I just loosen the cap on my master cylinder. So far no damage to the ABS pump.
You did not state the year model of the car and whether or not it has discs or drum brakes on the rear.
If it has drums, worn or seriously out of adjustment brake shoes can cause odd problems which often mimic a failing master cylinder, etc.
I just loosen the cap on my master cylinder. So far no damage to the ABS pump.
98caddy:
It looks like you missed the point Tester was making. Given the ABS is between the caliper and the master cylinder, loosening the cap on the master cylinder doesn’t prevent the back-pressure that you’re placing on the ABS solenoid valves.
My money is on a stuck slider in one of the calipers. Did the OP clean and lube all the sliders when the pads were replaced?
did your car originally come with organic pads? not sure an 01 year car would. but it is a cheap car. i changed pads on a car that were 2/3 worn. pushing pistons back into calipers and drove it and brake pedal went right to floor. had to bled brakes a lot and it eventually got about 9/10 pedal feel back. many folks say to crack bleeder screw before pushing piston back into caliper to allow old fluid which is filling void of extended piston. why push this dirty fluid back up into brakeline?
the original pads are semi-metalic organics would explain the soft pedal
Given that the brakes worked fine BEFORE the heavy braking, then afterwards there was a problem, I’m guessing the brake fluid boiled and now has to be flushed.
Do you have the calipers on the correct side??
They may look identical, but they aren’t. The bleeding nut should be on the high-side of the caliper when it’s mounted. If it’s on the low side…then you have the calipers on the wrong side…Just switch them.
98caddy: It looks like you missed the point Tester was making. Given the ABS is between the caliper and the master cylinder, loosening the cap on the master cylinder doesn't prevent the back-pressure that you're placing on the ABS solenoid valves.
No, I’m aware of that. Despite that fact, my procedure over probably 8-10 brake pad and/or rotor replacements on the car (by axle, not all four wheels) has been to loosen the cap on the master cylinder and press or screw in the caliper (depending on front or rear brakes). This makes the fluid level in the master cylinder rise.
Perhaps I’ve been lucky, or perhaps it doesn’t apply to my car.
There is clear grease sprayed on the rotors when they are packed to stop them from rusting. That grease is now soaked into your brake pads. It is a pretty good lubricant too which is why your car doesn’t want to stop. Remove your pads and rotors and clean the rotors ( use spray brake cleaner or dish detergent, hot water and a brush ) Then either throw the pads away ( my preference ) or take a belt sander to them until they seem clean.
My daughter had a brake job done at a local shop and they wouldn’t admit they had done the same thing. My son-in-law didn;t want to do anything about it and it was months before the car would stop right.
With all due respect 98caddy, pushing the brake fluid into the master cylinder is not the proper way to compress the piston. Doesn’t make any difference if you take the cap off or not, you are still pushing dirty fluid through the ABS unit. That can cause needless damage. It’s quite simple to just crack the fitting while pushing the piston back and directing the old fluid into a jar.
The skill levels vary on this board and its important not to needlessly lead people astray with procedures that were OK in the past but not in the last 15 years. Just do what the factory manual says.