jeff91C2T

I've got a nagging problem with my 965. The clutch pedal, after the car is warmed up, has to much play at the top of the pedal stroke.

When cold the clutch engages at the top of the stroke. When warm, the pedal goes down more then an inch before finally getting resistance.

My first thought is to bleed the clutch, and go from there. Any thoughts, comments on how to go about this?

thanks

Jeff Curtis

Bleeding the clutch certainly sounds like a good place to start in your troubleshooting. Bleeding the clutch master cylinder is easy.

1) Obtain a pressure bleeder and fill with desired brake fluid...I use ATE blue.

2) Attach fitting to BRAKE MASTER CYLINDER RESERVOIR, pressurize and bleed all of your calipers, both screws. Yes, your clutch hydraulic system "borrows" -or- "piggy backs" your brake system.

3) Leaving your driver's rear wheel off, slide underneath the vehicle and locate your clutch master cylinder, it looks like a miniature brake master cylinder.

4) Place a proper sized closed end or brake line fitting wrench over the bleed screw, then a piece of tubing heading attached to some type of catch can, I use a sports bottle.

5) Open up that fitting for awhile, if using a clear piece of tubing, you will see the benefits, if not, shake the catch can until you have a significant amount of used fluid in there.

6) Check the catch can, notice the NASTY black fluid in there? Huh, it used to be amber or blue, maybe clear...dump it out.

7) Crawl back under the vehicle and open the bleed screw again, for a shorter period of time, check your catch can and verify you have nice clean fluid in there now - if so, you are done!

8) Go out and enjoy your brakes and responsive clutch pedal! **put your driver's rear wheel back on first!!**

Adrian

Dear Jeffs both of you.
The 911 (964) Turbo has a high pressure brake system. 180 bar with a hydraulic pump booster not a vacuum booster as in the 911C2. Not a good idea to pressurise the brakes and then crack a line. You can bleed this system I believe easier than a C4 but it has to be be done with power off and the correct equipment.
There is a specific procedure for bleeding the clutch system but I am afraid I do not have it yet. This is in the Turbo manual supplements.
I advise Jeff 1 to find the manuals and review the process first.
Ciao,
Adrian
911C4

PS: On the C4 the manual clearly states (has the same brake system as the 964 Turbo), depressurise the system before cracking a line. The accumulator has 80 bar in it.

Larry Weinstein

Adrian,

Re. bleeding brakes on a C4.

I installed speedbleeders on my 91 C4 and just open each (of the 8) bleeders one at a time and press down the brake pedal until I've removed a sufficient amount of fluid...being careful to keep the reservoir level up. Is this a problem-I keep hearing about this "high pressure" system.

Thanks

Jeff Curtis

Me so sorry! I didn't catch that it was a 965 in question...guess these late night rants are getting to me!??

Adrian

Dear Larry,
What you are doing is "highly unrecommended" and you do run a high risk of problems. I assume you are doing this with power off.
Every time your press the brake pedal you are actually reducing the pressure in the system when power is off. 25 pedal pushes and your system is without pressure.
I guess you have been lucky and it is your choice but this is not the way to bleed your brakes on a C4.
Ciao,
Adrian
911C4

jeff91C2T

Well guys....I've been going over the 965 manual for bleeding brakes/clutch. Hmmmm, can't believe Porsche charges so much money for this material. I've seen better information in a Haynes manual.

Check this out...to bleed the clutch according to the manual (which was the original question) you should use an "appropriate bleeding and filling device". I'm assuming this is a pressure bleeder. The only info I can find specific to the clutch is "also drain approx. 50 to 100 cc of brake fluid at the clutch slave cylinder". That's a lot of help! Not even a picture of the damn thing

BTW....seems they've broken up the bleeding and replacing brake fluid into different steps. No mention of the need for the Hammer (just the pressure bleeder). It also does say the lines are to be cracked "Open bleeder valve slowly and keep bleeder hose fitted tightly. System pressure is up to 180 bar."

I almost gave up on this and went to a shop to have it done. They wanted $250 to do the job (brakes and clutch). Ya..right. I'm going to find the clutch master cylinder this weekend and let you know how it goes.

BTW...were is it

shaker71

I'm familiar with 964 so excuse me if this doesn't fit.

From reading the thread it seems that the subject was bleeding the clutch system, not the brakes. The two systems are independant except for the master cylinder that is shared.

I recommend you go to the Pelican Parts web site and read their clutch slave cylinder bleeding instuctions. This should make it easy as long as your a contortionist. You'll see what I mean when you go for the slave bleeder screw.

Bill

Bill Gregory

Article on how to flush the slave cylinder <a href="http://p-car.com/diy/slave/" target="_blank">here</a>

paulds

Actually the systems do not share the master cylinder but just the brake fluid reservoir. The clutch system and the brake system have their own master cylinders.

shaker71

Thanks for the correction... It must have been a late night for me too... The clutch has it's own master. Sorry

Bill