I just installed new brake pads today and now the pedal has very little pressure and hits the floor. I literally only pulled the pads, compressed the pistons enough to slide in the new pads and was done. I took the brake reservoir cap off just to compress the caliper piston and snugged it back up, otherwise I didn't touch the bleeders or anything else at all. Now the pedal goes to the floor. I've swapped pads on dozens of cars this way and never had this happen. Did the master cylinder fail coincidentally or is there an ABS reset procedure I need to run through?
Brake pedal hits the floor after installing brake pads
- Thread starter kris9884
- Start date
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- Thread starter
- #3
I drove it around the block and immediately had to turn around so I couldn't say for sure but, at least 8-9 times in a row. I parked it in my driveway and tried pumping the pedal but pressure didn't build. No leaks and the reservoir is still just below the max line. Brake fluid was flushed about 4k ago without issues. Zero rust, lines are minty.
If it was mine, I would take off each wheel and look at the brakes for signs of a leak. I’d start with the front, since those lines are stretched when the wheel is jacked up. Sometimes pushing the pistons in damages the seals.
Try pumping the brakes 100 times to see if pressure builds. Definitely watch the reservoir after the first 10/15 pumps to see if the level changes.
- Thread starter
- #7
Yeah, so I think i just needed more pedal time. Building them back up and putting the pistons to the pads took a couple dozen more pumps today. The pedal is back to normal and the fluid dropped back down a bit between the min/max. I've never had to do it so many times before but, meh.
Interesting. Were any of the pads sticky in the caliper? Was there any unusual difference in wear among pads? It seems to me (and with all the brake work I’ve done), the pads should move up to rotor and pistons up to the pads within just a couple pedal pumps.
I once encountered a similar problem. Bleeding/flushing the system the traditional way didn’t help. Somehow I can’t explain some air had found its way into the ABS pump. I was this close to replacing the master cylinder but decided to bleed the system using Techstream just for the hell of it.
Who would have guessed there was some air trapped in there! After the Techstream brake fluid flush all was well. Keep in mind the Techstream procedure will move whatever air was trapped in the ABS pump out into the lines, so you still need to flush the lines the traditional way after the Techstream procedure to get all the air completely out of the system.
Who would have guessed there was some air trapped in there! After the Techstream brake fluid flush all was well. Keep in mind the Techstream procedure will move whatever air was trapped in the ABS pump out into the lines, so you still need to flush the lines the traditional way after the Techstream procedure to get all the air completely out of the system.
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- Thread starter
- #10
So weird. I went out to drive it this morning and as the day went on/or the fluid heated up the pedal got worse so, there must be some air trapped in there. Although I didn't open the system at all, seems like there's air from maybe the ABS. I'll have to wait a day or two for some time but I have a good bi-directional scan tool and can try the ABS bleed procedure and then bleed all 4 corners as well. What better time to perform a brake flush than when you're really busy?
I use this when replacing fluid -- worth every penny.
I am thinking about grabbing one of these. Need to do brakes/fluid on the Macan.
Pneumatic Air Operated Brake Bleeder with Auto-Refill Kit
Amazing deals on this Pneumatic Brake Bleeder Kit at Harbor Freight. Quality tools & low prices.
Hmm...you sure?
I followed the FSM and it doesn't tell you to go back and bleed brakes again.
Master tech tip: open the caliper bleeder when you push the pistons in. Bleed system after all the work is finished. Don’t push all that crap back upstream.
Bleed the brakes, and use techstream if you have a copy to bleed the air out of the master cylinder and ABS. It’s an easy process.
For those doing brakes in the future, get a one man brake bleeder (they’re like $10), attach it, and crack the bleeder on the caliper when you push the piston back in so the excess fluid goes into the bleeder and not back into the master cylinder where it can overflow. When you’re done use it to change the brake fluid too.
For those doing brakes in the future, get a one man brake bleeder (they’re like $10), attach it, and crack the bleeder on the caliper when you push the piston back in so the excess fluid goes into the bleeder and not back into the master cylinder where it can overflow. When you’re done use it to change the brake fluid too.
- Thread starter
- #16
Little late on the update but I ended up performing the ABS brake bleed service via the scanner. After letting that do its thing for 20 mins or so, I bleed all 4 corners using my old Gatorade bottle method. Worked like a charm, put about 600 miles on it since. All is well.