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OP, two concerns: 1) No mention of bedding the new pads. Not bedding the pads could be the reason you're seeing the glazing. 2) ABS actuating at relatively low speed. I'm a year and 5k miles of ownership of my '09 Carrera and have never seen this, even under firm braking - though I doubt I've been near ABS threshold.
You should see a difference with the new pads. The only other suggestion I'd have is to change the flex brake lines with some SS ones (I did this). They're inexpensive.
Last edited by swingwing; 11-24-2018 at 10:04 AM.
Reason: Added wording.
If the rear parking brake is adjusted incorrectly, you could get the rotors hot enough to glaze the regular pads even though they're not the ones used by the parking brake. I have no issues with braking ability on my wife's C2S using the Hawk Ceramics, in fact I prefer their lower initial bite to the "grabby" pads I end up driving on a lot of rental cars, as it makes the braking easier to modulate
Pads were bedded in as per hawk instructions. Few stops from lower speed and few from a higher speed. Can’t remember the exact speeds now but never came to a full stop. Then drive around on the freeway without using the brakes for about 20 mins.
will check parking brake again but I do remember making sure they don’t touch the rotor when parking brake is off. It’s been about 2 months since I drove my car the way it’s meant to be driven. Waiting for parts, swapping things out etc has been quite time consuming.
I use my car daily, weekend- track,canyon run everything it’s not a garage queen and 2 months is longest ever it’s been off the road, what a disappointment. Really hoping the new ferodo pads solve the issue. Else it’s new rotors which again involves waiting for parts.
New ferodo pads front and rear. Went out for a drive to bed them in as per ferodo instructions.
Obervations were the front brakes are biting hard enough to activate the abs. Rear brakes lack serious bite. Anyone know what the brake bias is for the 997? 60/40 front rear?
i drove for about 30mins with some aggressive braking and then cooling off. Front brakes were still quite hot to the touch but the rear rotors were actually just warm. It’s definitely not braking enough at the rear. It’s like the pads are not biting the rotor hard enough.
Examined the caliper pistons,seals. No leaks, pistons move in and out freely though I don’t have a tool to measure how much force the pistons exert. Then took the brake line off the rear calipers and asked someone to step on the brakes and lots of fluid comes out evenly out of both sides.
I even swapped the abs wheel speed sensors from front to rear and no change in brake performance.
Also checked the parking brake as well and everything looks good and does not touch rotor when disengaged.
Only thing remaining is now is the abs module/pump unless you guys can suggest something I’m missing.
Rear rotors are above minimum thickness but I’ve never experienced a worn rotor cause significant brake degradation unless it was warped.
Now I have an U0418 code. Can fault brake. Not much info about it online, could be wiring issue. Strange that it could cause just rear brakes to go weak.
might be easier to swap out abs module and pump first than go chasing wiring issues which could take ages.
Now I have an U0418 code. Can fault brake. Not much info about it online, could be wiring issue. Strange that it could cause just rear brakes to go weak.
might be easier to swap out abs module and pump first than go chasing wiring issues which could take ages.
Now we're getting somewhere. That's a Can Bus network error code. It should occur in a specific module, but could also be caused by anything on the Canbus network of the car, which is a lot of things. Let's start with the basics - what is not stock on the car that might be tied into the canbus network. I don't see in your posts if your car is an S or non-S (helps to have your year and model info in your signature).
If an S, the PASM suspension control module & stock 3-axis accelerometer
PCM system - anything added do it or not stock (bluetooth kit, MOST adapter, aftermarket radio or amps, etc)
if a PDK car, the transmission
That error is also sometimes a module coding problem where for some reason a module on the canbus stopped communicating correctly with the car and needs to be recoded to it. That's going to be a dealer function with PIWIS, but it that was the brake controller, that could certainly cause the braking issue you've been seeing.
Out of curiosity, does it behave the same way if you turn off PSM (stability management) and put PASM in Sport mode - this opens up the threshold for ABS and stability management a bit and if it then behaves differently, that will point you in a direction of something involved with those systems.
Just to update this thread, everything sorted. It was a faulty abs module. The electronic brake distribution was not working properly and rear brakes were not activating hard enough. Changed the abs module, got it programmed to car with a piwis. New ferodo pads all around, upgraded to the 4s/gt3 master cylinder as well. Everything is back to normal. The ferodo ds2509 pads are fantastic when it comes to braking but quite noisy (even with brand new Porsche anti vibration shims all around.
The canbus fault code has also seemed to go away but it was a very intermittent code so will keep monitoring to see if it comes back.
11-24-2018, 09:11 AM
