Brake problems after brake job

shadowx360 · 05-17-2014, 12:00 AM

Hey, I got a question for you guys. I was having brake judder problems from probably being too hard on my brakes so I decided to do a full brake job with new R1 Concept rotors and ceramic pads and replace the piston seals.

I didn't have a pneumatic tool to push the pistons out so I just took the calipers off and pumped the brakes until the pistons came all the way out. Cleaned and installed new seals. I noticed air was sucked in from the reservoir while I did this. Installed new rotors and pads. Left it overnight in my garage and then int he morning, I bled my brakes first using a vacuum bleeder tool and 32 fl oz of Dot4 brake fluid, then had a friend come over and bleed by pumping the brakes, in order by distance from master cylinder. Ran through another 32 oz of fluid, noticed only a couple of very tiny air bubbles in the first few pumps. Basically removed 4 fl oz of fluid from each bleeder screw every time, so total of bleeding each piston 4 times.

I bed my brakes but during this, I noticed brake travel was much higher and the pedal definitely felt spongy. Originally, my brake pedal used to be very very firm. My braking power does not seem to be reduced as I can make my tires screech before I push it all the way down. However, I definitely have to use more force and press it much deeper to get the same braking power. At a complete stop, I can push my pedal down to the floor, something I could not have done before. Also, if I keep pumping my pedal at a stop, the pedal gets higher every time. If I use force, I can force the pedal slowly back down to the floor after the pumps.

What can be the issue? I don't think it is air because I used up half a gallon of brake fluid. Other suggestion usually thrown around is that the ABS unit was not bled but I don't think air could have gotten in because the valves are usually closed (unless they open if you turn your car off and leave the brake lines dripping overnight?). I don't think it is a master cylinder problem either because that was fine before I did all of this. Out of ideas now, and it's been a few days of very hard driving to see if that would fix the problem but it hasn't.

Thanks in advance for any insight.

minhsnyc · 05-17-2014, 11:27 PM

Silly thought but make sure the calipers didn't get crossed when you took both off. Bleed screw should be on the top and not the bottom.

05-17-2014, 12:00 AM	#1
shadowx360 Private First Class 41 Rep 146 Posts Drives: BMW 340i Join Date: Apr 2013 Location: United States iTrader: (0)	Brake problems after brake job Hey, I got a question for you guys. I was having brake judder problems from probably being too hard on my brakes so I decided to do a full brake job with new R1 Concept rotors and ceramic pads and replace the piston seals. I didn't have a pneumatic tool to push the pistons out so I just took the calipers off and pumped the brakes until the pistons came all the way out. Cleaned and installed new seals. I noticed air was sucked in from the reservoir while I did this. Installed new rotors and pads. Left it overnight in my garage and then int he morning, I bled my brakes first using a vacuum bleeder tool and 32 fl oz of Dot4 brake fluid, then had a friend come over and bleed by pumping the brakes, in order by distance from master cylinder. Ran through another 32 oz of fluid, noticed only a couple of very tiny air bubbles in the first few pumps. Basically removed 4 fl oz of fluid from each bleeder screw every time, so total of bleeding each piston 4 times. I bed my brakes but during this, I noticed brake travel was much higher and the pedal definitely felt spongy. Originally, my brake pedal used to be very very firm. My braking power does not seem to be reduced as I can make my tires screech before I push it all the way down. However, I definitely have to use more force and press it much deeper to get the same braking power. At a complete stop, I can push my pedal down to the floor, something I could not have done before. Also, if I keep pumping my pedal at a stop, the pedal gets higher every time. If I use force, I can force the pedal slowly back down to the floor after the pumps. What can be the issue? I don't think it is air because I used up half a gallon of brake fluid. Other suggestion usually thrown around is that the ABS unit was not bled but I don't think air could have gotten in because the valves are usually closed (unless they open if you turn your car off and leave the brake lines dripping overnight?). I don't think it is a master cylinder problem either because that was fine before I did all of this. Out of ideas now, and it's been a few days of very hard driving to see if that would fix the problem but it hasn't. Thanks in advance for any insight.
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05-17-2014, 11:27 PM	#2
minhsnyc wooord 3 Rep 37 Posts Drives: 14' 335i M-Sport Join Date: May 2014 Location: Brooklyn, NY iTrader: (0)	Silly thought but make sure the calipers didn't get crossed when you took both off. Bleed screw should be on the top and not the bottom.
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