zellamsee

Help! I recently put new rotors and pads on my Spyder (and flushed the brake fluid too). All parts are stock, and I don't have PCCBs. The pedal feel was really good -- a nice hard/firm pedal. About a week ago or so I tracked the car on a very hot day, and thereafter my brake pedal was really soft and mushy. I could almost push the pedal to the floor! I assumed that I had cooked the brake fluid, so I replaced the fluid -- this time with Castrol SRF. However, even after the flush my pedal feel is still not as firm as I remember. I tracked the car again yesterday, and while the fluid didn't boil, again, my pedal feel isn't as firm as I remember. Too much travel, and too mushy.

Any clues as to what may be going on? Perhaps my pads (although relatively new) are gone? I think the master cylinder is working, given that when the car is off, a quick pump of the brakes results in a firm pedal. I am at a loss as to how to fix things here, without replacing lines and/or the master cylinder (GT3 upgrade, if that even helps). Any insights much appreciated.

ECS Tuning

orthojoe

MMMmmm. My favorite thread subject. Mushy brake pedal. It seems like everything is working just fine with a new flush of fluid and solid pedal with pump of brakes when the car is off.

What you're describing now is the way I've always felt the brakes to be normally. The discrepancy is that you feel like the brakes used to feel good and they've changed in character at this point. You're sure that you're not just more aggressive with the brakes now and are just noticing the issue? Thinner pads shouldn't affect the pedal feel. I dont think glazed pads would do that either....

khooni

Don't rush into a fix before identifying the root cause. speak to your trusted mechanic/dealer on this.

Macster

What technique did you use to flush the brake fluid?

Sincerely,

Macster.

zellamsee

Thanks guys. To answer a few questions:

1. I track about 7x per year.

2. I do sometimes wonder if I am remembering the harder pedal (correctly)! That is, perhaps the "softer" pedal is just in my head. In any event, it is just too mushy.

3. I had my Porsche dealer do the flush. Not sure what they did. I will ask.

orthojoe

Which groups do you run with? Have you met Ben yet (he's at the track frequently)? I do about 6 events a year with NCRC, TMR, and HOD. Hope to meet you sometime at the track to talk. I'll be at Laguna on Oct 20th with NCRC in the open group with Ben.

Since you feel a difference, I would make sure that everything in the system is working correctly as Khooni suggested. I bleed my lines with the Motiv power bleeder. If the dealer did your flush I can only assume they did it correctly. If everything checks out, you can join my club and get a GT3 master cylinder to decrease that pedal travel.

San Rensho

If you used stock pads, they are probably just degraded from the high heat, even though they are not worn. I put new Mintex pads on my car and at first they had fantastic bite, but after 2 track days the front pad material has turned yellow and the braking ability has degraded slightly, mostly the initial bite, even though the pads are only worn about 1/4 from new.

I think its just the street pads don't hold up well at the track.

orthojoe

I think you make a good point. It might just be the pads wearing down making the difference. Many guys have been happy with their stock master cylinder, and some have noticed that track pads have improved pedal feel. It would be interesting to see if a fresh new set of pads brings back the pedal feel that you remember on the car. OR, you can be like me and never be fully satisfied with how your brake pedal feels.

5500

Had a similar experience with my CR. Pedal travel/feel is fine on the street but excessive pedal travel once the brakes were heated up at the track (brakes worked okay, just took way to much travel & soft pedal IMO).
Swapped MS for a 997 GT3 item, problem gone. Its a well documented issue with Caymans and most have found the MS swap the most helpful remedy. Unless you're unsure of your bleeding skills, its the MC.

khooni

Orthojoe and 5500,

I now agree with you on this. The CR/spyder setup for brakes is excellent on the street. Allowing easy heel toe butat the track, the steel brake setup doesn't give as much confidence due to the longer travel and softness. But, they stop. At least for a 20 min session on my local track. the PCCbs give much better confidence and are definitely better on track, but modulation is still better on the steels (IMO). Nonetheless, I can now definitely understand the motivations behind this.

Re brake pads and stainless steel brake lines, they used to work wonders (firmer feel) on my old wrx when upgraded so as a simple fix (if brake fluid is not the issue), i'd try that first before jumping on the bandwagon and losing some street flexibility with the brakes. I wonder if just upgrading the brake lines will work.

fyi, on my PCCB equipped spyder, it is definitely not as fun to drive on the street as my CR and that is partly down to the brakes. anyway, have fun experimenting.

11Spydr

Please note that I am not (yet) tracking my Spyder but FWIW from initial delivery (08/10) I noted longer pedal travel & a much softer feel than on the 2002 Boxster S the Spyder replaced. Because of the comments re. Spyder brakes on various forums & juat assumed this was normal & I did nothing about it.

At 2 years of service I did a flush & bleed (Motive Bleeder & Porsche brake fluid) & I noticed that I had air bubbles coming from the passenger side wheel cylinders. With the flush & bleed completed I noted that I had a much higher & firmer brake pedal so I am suggesting that before making any changes in the braking system you have a qualified person do a bleeding procedure again using a Motive Bleeder or similar system . You may simply have gotten a poor flush & bleed job from the dealer.

orthojoe

Glad to hear the GT3 MC worked for you. I'm happy I did the swap because of the decreased pedal travel, but I'm still not totally happy with my pedal feel. I must be one of the few here that prefers a rock hard, solid, endpoint when slamming on the brakes. In the beginning I kept on doubting my ability to properly bleed the lines. However, I've done it over and over multiple times with no change. When I bleed my Evo with the same technique, the brake pedal is solid as a rock and is PERFECT (motiv power bleeder and motul rbf600 fluid).

Khooni, I knew I'd break you down eventually. Can you explain why you think the decreased pedal travel would detract from the experience driving on the street?

Did the flush/bleed you did make the pedal feel just as good as the '02 boxster S? In my experience, the 986 brake pedal is MUCH better than the 987.2. The 986 has a solid endpoint, whereas the 987.2 is still mushy (no experience with 987.1).

Marine Blue

There is no doubt that the brakes do not inspire confidence, even for street use. When I slam that brake pedal I expect to hit a wall when it comes to stopping power and when you consider the weight distribution, weight , caliper/disc size and amount of tire on the pavement you would think it should be easily achieved with the Spyder. The funny thing is that it's usually the tires that are the limiting factor, but in this instance it is clearly another cause.

To top it off the pads generate enough dust that air quality anywhere near the car must be poor!

11Spydr

Ortho Joe

Re. improved brake feel after bleed. Since it's been over 2 years since I've driven a 986 so I can't say if the Spyder brakes feel is as good or not. From memory it seems like the Spyder brakes don't have quite as much initial "bite" (factory pads on my 02 S) but can say that I'm now well satisfied with the brake feel on my Spyder (at least for street use).