964 clutch pedal not returning

John Pedersen · 05-18-2008, 09:37 AM

I just purchased a 1993 964 and noticed the clutch pedal will not return the last two inches it just stays there, works fine but you need to pull back with your foot. I did a search on this but it only mentions the 993 with this problem. I have a receipt the clutch slave cyl was just replaced last year and the clutch blead. There is no leaking at the clutch master cyl, but the boot was torn. I greased the master piston shaft but still sticks. Any ideas?

Don Plumley · Don Plumley's Garage

Sounds like air the system - might be a seal in the MC. Do you know how to bleed the clutch?

John Pedersen · 05-18-2008, 10:36 AM

Don
No never had anything this new before! Mostly SC 911's. Is there a tech article on this?
John

Don Plumley · Don Plumley's Garage

Here's a DIY for a 993 - same general idea.

John Pedersen · 05-18-2008, 01:02 PM

Thanks Don!

John Pedersen · 05-18-2008, 01:02 PM

Thanks Don!

scooter911 · 05-18-2008, 04:03 PM

Mine was the same way and no one ever fixed it after bleeding adjusting the pedal spring...When I replace the clutch the problem went away. I would just live with it...

Tom W · Tom W's Garage

It's likely the master or slave. Has happened to me twice over the years and it definitely was not anything related to bleeding the system. You'll read about a "kinematic pedal" fix for the 993 too - ignore it as it does not work for the 964 (different pedals).

John Pedersen · 05-18-2008, 05:37 PM

So the question is if the pedaal is down the 2 inches not in the complete retun position, is it doing damage to the disc, or t-o bearing??
John

bazar01 · bazar01's Garage

Quote:

Originally Posted by John Pedersen

So the question is if the pedaal is down the 2 inches not in the complete retun position, is it doing damage to the disc, or t-o bearing??
John

The real question is if you are getting full disengagement on the clutch to be able to shift smoothly without grinding on the gears. If the pedal is 2" down from full return, I doubt the clutch will disengage fully to get a smooth shifting. You might damage the transmission and G50s are expensive to repair or replace while hydraulic clutch components (slave and master cylinder) are cheap.

voodoo964 · 05-19-2008, 01:47 AM

I have a 1993 964 also, have exactly the same issue. I had a PPI with Peter Morgan in the UK - he noted this issue but it appeared to be the spring in the pedal so didn't affect the clutch. To be honest it seems like that last bit of travel has no effect on the clutch so i wouldn't worry about it. One of the guys mentioned a "kinematic pedal" fix - the late 964s use some of the 993 components so i wouldn't be surprised if the fix worked.

John Pedersen · 05-19-2008, 03:52 AM

At this point since the slave was replaced last year I think I will get a clutch master, since the car has 98k and the boot is ripped. Also, car shifts fine no grind, like the 2 inch gap means nothing!

boeing 717 · 06:52 AM

Hey John, i had the exact same issue with my 964 turbo. When i got everything apart i noticed the clutch slave hydraulic line was totally rotted and it was really soft because the rubber outer portion was gone. That causes the hose to balloon and collapse everytime you use the clutch. I replaced the hose which is only like 40 dollars and bled the system, PROBLEM SOLVED, clutch pedal comes all the way back every time!!!

Check it before you spend a bunch of money on a master or something.

Congrats on your purchase!!!!!

Good luck

JERRY

John Pedersen · 05-19-2008, 07:57 AM

Thanks Jerry
The slave and hose were replaced last year only 4k miles ago, so I am still thinking clutch master is bad.

bazar01 · bazar01's Garage

Have you tried bleeding the master yet? When I bled the slave a a while back, the pedal just dropped to the floor. It sucked air and I gave up bleeding the slave. I ended up bleeding the master through the hard line fitting in the back of the master and continue bleeding the slave afterwards. It's been working flawlessly ever since.
It could have been easier with a power bleeder but I did not have one. It's worth a try.

boeing 717 · 05-19-2008, 10:15 AM

Yea John... Bazar may be right. I had to bleed my slave three times. The first time the pedal dropped to the floor. Finally it had no more air in it. You may want to try that first to make sure its not something simple like that. I used a power bleeder and its still kinda tricky.

Good luck

JERRY

John Pedersen · 05-19-2008, 11:56 AM

OK just to get this correct, when you bleed the slave you are also bleeding the master at the same time?? Do you need to pump the pedal or just use a power bleeder at the brake master as this is same fluid used?
John

boeing 717 · 05-19-2008, 03:20 PM

John i think thats correct, if you bleed the slave... the master is also bled but im not 100% positive. You need a power bleeder to connect to the brake fluid resevoir. Cant pump the pedal if im not mistaken. And the aft portion of the brake fluid resevoir is where the clutch fluid is stored (its divided into sections) so you need to make sure its kept full when you bleed.

JERRY

Tom W · Tom W's Garage

You can pump the pedal to bleed the slave, but it is a 2 person job to coordinate to avoid getting air into the system. (Bleed when the pedal is pushed to the floor and stop before it is released)

red63 · 05-20-2008, 04:31 AM

I used a powerbleeder on my 1990 to bleed the whole system. I don't pump the bleeder up past 10 or 15 (PSI?) on the guage. The system bled just fine but the clutch was all the way to the floor when done. The trick was vigorously pumping the clutch after bleeding (system closed) and after 10-15 pumps the pressure built up. 20+ pumps and everything was fine.

I read that the power bleeder should be pumped up much higher. I suppose that is meant to keep the pressure up in the system. My bleeder leaks too much to keep a high pressure in the bottle.