Rear brake problem
#16
Drifting
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Got the car back today.
Dust caps removed.
Installed clamps so pucks don't fall out.
caliper nuts installed instead of the OEM bolts.
Replaced brake fluid with Castrol SRF.
And of course new rear brake pads![Big Grin](https://rennlist.com/forums/images/smilies/biggrin.gif)
Read to go
Dust caps removed.
Installed clamps so pucks don't fall out.
caliper nuts installed instead of the OEM bolts.
Replaced brake fluid with Castrol SRF.
And of course new rear brake pads
![Big Grin](https://rennlist.com/forums/images/smilies/biggrin.gif)
Read to go
![thumbup](https://rennlist.com/forums/graemlins/thumbup.gif)
#17
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Oddly enough, I had almost the identical experience two weeks ago at NJMP. My rears were getting down but it looked like I had enough left. Wrong. Both rear inner pads went down to metal, the pistons overextended, the left rear started to spurt brake fluid on each brake application. My first warning was a soft pedal that didn't get better and quickly got worse until, by the time I got to pit in, I had almost no brakes. By that time, my left rear caliper was on fire. I'm told that I had fire and big smoke on each brake application for at least a lap but the corner workers didn't notice!?.
The fire burned out on its own. I removed the calipers, pushed the overextended pistons back, installed new pads, and (after testing) ran the rest of the day without mishap but with heightened sensitivity in the heavy brake zones. The rear calipers will be rebuilt before I go out again.
Teaching point? Rear calipers can go down way faster than you think and must be replaced at 50%. I always run with TC off so that wasn't the problem.
The fire burned out on its own. I removed the calipers, pushed the overextended pistons back, installed new pads, and (after testing) ran the rest of the day without mishap but with heightened sensitivity in the heavy brake zones. The rear calipers will be rebuilt before I go out again.
Teaching point? Rear calipers can go down way faster than you think and must be replaced at 50%. I always run with TC off so that wasn't the problem.
#18
Addict
Rennlist Member
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Oddly enough, I had almost the identical experience two weeks ago at NJMP. My rears were getting down but it looked like I had enough left. Wrong. Both rear inner pads went down to metal, the pistons overextended, the left rear started to spurt brake fluid on each brake application. My first warning was a soft pedal that didn't get better and quickly got worse until, by the time I got to pit in, I had almost no brakes. By that time, my left rear caliper was on fire. I'm told that I had fire and big smoke on each brake application for at least a lap but the corner workers didn't notice!?.
The fire burned out on its own. I removed the calipers, pushed the overextended pistons back, installed new pads, and (after testing) ran the rest of the day without mishap but with heightened sensitivity in the heavy brake zones. The rear calipers will be rebuilt before I go out again.
Teaching point? Rear calipers can go down way faster than you think and must be replaced at 50%. I always run with TC off so that wasn't the problem.
The fire burned out on its own. I removed the calipers, pushed the overextended pistons back, installed new pads, and (after testing) ran the rest of the day without mishap but with heightened sensitivity in the heavy brake zones. The rear calipers will be rebuilt before I go out again.
Teaching point? Rear calipers can go down way faster than you think and must be replaced at 50%. I always run with TC off so that wasn't the problem.
- Add rear brake cooling ducts.
All nannies off in my Cayman still leave the rear ABD active, I won't be surprised if the GT3 does the same, because the GT3 should wear the front brakes much more than the rear ones (weight distribution during braking).
#19
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
![Confused](https://rennlist.com/forums/images/smilies/confused.gif)
other way around. GT3 has less effective front wheel braking torque than a cayman (given the same tire and conditions) therefor should have more even brake bias than a cayman.
Dynamic weight distribution under braking
58/42 GT3
64/36 Cayman
#20
Nordschleife Master
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Daredevil (Derek) from Montreal had similar experience with the PFCs on a 996 Carrera, but he said something about the inner pad breaking up and falling out, leaving him with only the back plate.
He spoke to PF, and they told him that it was due to running street rubber on a "stock" car with abs, etc, etc. I'll try to get him to chime in.
It's a good thing that these PFC pads are good right to the backing plate
He spoke to PF, and they told him that it was due to running street rubber on a "stock" car with abs, etc, etc. I'll try to get him to chime in.
It's a good thing that these PFC pads are good right to the backing plate
![ducking](https://rennlist.com/forums/graemlins/icon107.gif)
#21
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
- Replace the caliper pistons, rubber caps, essentially rebuild those rear calipers.
- Add rear brake cooling ducts.
All nannies off in my Cayman still leave the rear ABD active, I won't be surprised if the GT3 does the same, because the GT3 should wear the front brakes much more than the rear ones (weight distribution during braking).
- Add rear brake cooling ducts.
All nannies off in my Cayman still leave the rear ABD active, I won't be surprised if the GT3 does the same, because the GT3 should wear the front brakes much more than the rear ones (weight distribution during braking).
#22
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Daredevil (Derek) from Montreal had similar experience with the PFCs on a 996 Carrera, but he said something about the inner pad breaking up and falling out, leaving him with only the back plate.
He spoke to PF, and they told him that it was due to running street rubber on a "stock" car with abs, etc, etc. I'll try to get him to chime in.
It's a good thing that these PFC pads are good right to the backing plate![ducking](https://rennlist.com/forums/graemlins/icon107.gif)
He spoke to PF, and they told him that it was due to running street rubber on a "stock" car with abs, etc, etc. I'll try to get him to chime in.
It's a good thing that these PFC pads are good right to the backing plate
![ducking](https://rennlist.com/forums/graemlins/icon107.gif)
Driver-front, inside pad, lost all the friction material. While remove the passenger-front, inside pad, the material slid off the backing plate.
These are PFC01's on a stock '02 996.
In a nutshell, PFC told me that the combination of using drilled rotors and the abs system ruined the pads and led to their failure.
In their words, the drilled rotors act a cheese grater (greater drag). This builds up heat in the pads very quickly. The reduced surface area of the rotor (being drilled) isn't pulling enough heat away from them.
In addition, they suspect the abs is over active, due to tracking with street tires, and further contributing to pad degradation.
Their suggestion was: use a less aggressive compound if I maintain the drilled/street tire setup or upgrade to their floating rotor (slotted) setup.
I swapped out the 01’s for 06’s in the front and retained the 01’s in the rear.