STLPCA

Since my car was delivered I've thought the brake pedal felt soft & had too much travel, although braking was ultimately strong & I can get into ABS. I've compared pedal travel w/2 other CS' & mine, unlike the others, goes almost to the floor under hard pressure.

It's not been a big problem on the street, but it's really disconcerting on the track where a lack of trust in my brakes slows me down almost as much as the brakes & heel & toeing is difficult under hard braking.

I flushed the system w/ATE Blue & then re-bled. No improvement. I then had my dealer flush it again w/o improvement. Diagnostic checks showed nothing wrong, but Porsche authorized my dealer to replace the master cylinder (made no sense to me, but what do I know?). Still no improvement.

I've begun to suspect a bad hose that is expanding under pressure allowing the pedal to drop. Has anyone had a similar experience? Anyone have any ideas? Track weekend coming up fast & I'd like not to soil my pants coming off the straight.

morefun

I encountered the same problem when I purchased my CS. "Out of the box" at @ 1,500 when I first bled the brakes there was an inordinate amount of air in the system. If you peruse the Caymen Club forums you'll find that is norm. Try bleeding the system first.

Happniess is a firm brake pedal!

STLPCA

If you reread my post you'll see I flushed the system w/ATE Blue & then re-bled. No improvement. I then had my dealer flush it again w/o improvement.

I wish it were, but it's not as simple as air in the system.

morefun

Whoa! Gulity as charged, I was multi-tasking and obviously didn't finish reading........... Phone, dog, kids etc.. Next time! Curious as to what the problem turns out to be.

FWIW last weekend I flushed out the ATE and replaced it with SRF - it really firmed up the pedal.

FTS

Dan, interesting problem truly. I certainly haven't had that issue, but my rotors are no longer evenly surface that I need to deal with soon.

I would imagine the only thing left to try is really the brake lines, may SS lines might be a good test to isolate the issue; possibly changing them one corner at a time, but probably that would be over doing it. Good luck.

FTS

Sshhhh!

Btw, Stoptech SS lines for Boxster S fit perfectly onto the CS, which I have been using for over a year.

Chris Prack

While I have not experienced this problem with a Porsche yet, I have had this experience with a BMW. E36 M3 to be specific.

What I would suggest is to jump the ABS pump relay so the pump runs while you are bleeding the system. I would think that the dealer would have used the PIWIS tester to bleed the system when they did the MC but since it was a warrenty job they probably just pressure bled it. Who knows.

You may just be able to simply jump the pump relay without opening the system and let it run for a minute or so and then disconnect it and bleed it normally. If it does not get better then bleed it while the pump runs by opening the bleeder then jump the relay to turn on the pump. The fluid will come out pretty fast but should not be under very high pressure. Either way just use common sense and don't put your face over the bleeder.

99firehawk

I would not recomend doing that at all.......
Is the pedal spongey or is there just 2 much travel?

STLPCA

Again, it is NOT air in the system.

Brad
Although the pedal is softer than my prior 993, that's normal w/newer Porsches. The problem is too much pedal travel on a very hard brake application. The pedal goes down almost to the floor before the brakes really grab. It feels to me like an expanding line, but my dealer has to follow PCNA's service protocols, so what I think doesn't matter much..

99firehawk

jack up the car, or lift it on a lift, have some turn a wheel as you appy the brakes. how much travel till it locks the wheel ?
there is adjustment on the brake booster to adjust pedal height

Chris Prack

Really? Why is that? Just curious.

Chris Prack

The adjustment is used to set the toe play in the pedal. You do not want to start adjusting the rod to compensate for a low pedal. It's not a problem with the rod, it hasn't changed. Something else is wrong with the car and that is not it.

99firehawk

the pump on 9x6/9x7 cars also contains the abs module, there really isnt a relay to jump you would have to jump pins, pump is desigend to be bleed using the tester, and it only bleeds trhough the right front circut through a special bleed function , having other cicrcuts open and powering the pump could result in pump damage or excessive air in the system.

99firehawk

that is true the pedal adjustment is only for free play, but if the pedal feels fine and not spongey, and it has been thie way since new it could be misadjusted from the factory. Its really a hard thing to diagnose over the internet and would be much easier to physcaly see the car. IM not recomending that he change anything or adjust anything, im just suggesting possiblitiys, as with anything trying to acuratly diagnose a problem over the internet is simialr to calling the doctor and telling him your chest hurts and asking him why over the phone

STLPCA

This is a follow-up to my original post now that I've resolved my excessive pedal travel problem.

I've been driving Porsches for 20+ years & always loved their rock solid brake pedals so my CS experience was, to say the least, upsetting. After much work by my dealer we concluded that my soft pedal & excessive travel at the track were a combination of 2 factors: (1) a higher level of brake boost than I was used to from my previous P cars making the pedal effort much softer & (2) fading of my oem Textar brake pads on the track so that when they got hot they didn't grab until near the floor. Frankly, I hadn't considered the later possibility because in tracking my 993 I had used the oem pads & never had any fade. However, I'm carrying considerably more speed into brake zones w/the CS & perhaps the CS' oem Textar brake compound is different, but in any event the result was significant fade. At street temps, the pads were fine.

I've gotten used to the soft pedal so it's no longer an issue. I completely solved the fading by using Pagid Yellows (RS19) for track (thanks to help from Craig, owner of *********.com). My track pedal is now acceptably firm & pedal travel is now the same on the track as on the street, i.e., good. My braking confidence has been restored with the Pagids. Plus, wear so far has been much, much better than the stock pads.

I still use the oem Textars for the street w/o problems. Hope this is helpful for you.