New brake pads too tight.

[JSVice]

Just put on new rotors and pads. I triple checked the part numbers to make sure they were right for my '97 1.9l Z3. Before putting the new pads on, I took a C-clamp and made sure that the caliper piston was fully seated. The new pads are snug to the point of rubbing against the rotors without the pedal being applied. I can even tell that I have to give the car just a few more RPMs to get going in 1st or reverse. When it's up in the air, the passenger side will spin, but still rubs. The driver side takes a bit more effort and won't even do one complete revolution before stopping on its own. The pads were Powerstop Evolution model 16-558. Is there any chance in the world, that these pads can just be a hair too thick for my car? The new rotor was the same thickness as the one that came off. 90% of the time, the problem I'm describing is a result of a piston forcing the pads out. That's not the case here, believe me. I've had the calipers off enough to know.

 

[t-tony]

What condition are the flexible brake hoses in. They can breakdown inside and not release the applied pressure fully resulting in slight binding of the pads. I am assuming that when the piston is pushed back the brake spins free until it has been applied.
Also, did you ensure that the slider pins are clean and move freely? Sometimes you have to remove the rubber sleeves which the slider pins move in and clean the metal lugs where the rubbers fit.

Tony.

 

[mrscalex]

I’d also check the caliper carrier. If it’s crusted up the pad won’t slide properly.

 

[JSVice]

What condition are the flexible brake hoses in. They can breakdown inside and not release the applied pressure fully resulting in slight binding of the pads. I am assuming that when the piston is pushed back the brake spins free until it has been applied.
Also, did you ensure that the slider pins are clean and move freely? Sometimes you have to remove the rubber sleeves which the slider pins move in and clean the metal lugs where the rubbers fit.

Tony.

The hoses "look" ok to me. No obvious problems. The wheel does NOT spin freely, even immediately after clamping the piston and reassembling. I took the slider pins out and cleaned/lubed them.

 

[JSVice]

I’d also check the caliper carrier. If it’s crusted up the pad won’t slide properly.

There is no sliding. When I put the pads on, they're tight. All I can think is that these pads are just too darn thick, but if that were the case, surely more people would have had this problem.

 

[t-tony]

I have had this issue in the past with non-genuine after market pads. One thing you can do, and I have had to do, is take a sheet of 80 grit abrasive paper and lay it on a flat surface, then place the pads with the material face down and gently rub the pads till they're a nice fit. Wear a mask and do this in a well ventilated space.

Tony

 

[JSVice]

Good to know. At least it isn't just me.

 

[colb]

I changed my front pads on my daily driver Ssangyong Korando, found the new pads were a tight fit not because of the pad thickness but the metal edges of the slider shapes being a tad oversize so they didn't slide smoothly in the calipers. Needed to trim them down on a grinder so they fitted better with no chance of them getting stuck.

 

[Nodzed]

Just put on new rotors and pads. I triple checked the part numbers to make sure they were right for my '97 1.9l Z3. Before putting the new pads on, I took a C-clamp and made sure that the caliper piston was fully seated. The new pads are snug to the point of rubbing against the rotors without the pedal being applied. I can even tell that I have to give the car just a few more RPMs to get going in 1st or reverse. When it's up in the air, the passenger side will spin, but still rubs. The driver side takes a bit more effort and won't even do one complete revolution before stopping on its own. The pads were Powerstop Evolution model 16-558. Is there any chance in the world, that these pads can just be a hair too thick for my car? The new rotor was the same thickness as the one that came off. 90% of the time, the problem I'm describing is a result of a piston forcing the pads out. That's not the case here, believe me. I've had the calipers off enough to know.

As said make sure the runners for the pad hooks are clean, paint and rust / dirt free.

I changed my front pads on my daily driver Ssangyong Korando, found the new pads were a tight fit not because of the pad thickness but the metal edges of the slider shapes being a tad oversize so they didn't slide smoothly in the calipers. Needed to trim them down on a grinder so they fitted better with no chance of them getting stuck.

Agree Colin, had this many times over the years usually a file will sort it out.

 

[t-tony]

Ideally you want to use a “brake” file. These have very coarse teeth and will only remove the scale which builds up but not the steel itself. If you take off much of the steel you can get chatter where the pads move up and down in the carrier.

Tony.