Mike951

'95 968 : Finally got the failed weld on firewall around master cylinder fixed, went to bleed brakes and clutch, brake pedal fine, but clutch pedal is rediculously stiff. It seems to be disengaging the clutch fine, but is just way to stiff to be normal. Car sat for a while, 4 years or so. What are the typical causes of a stiff clutch pedal?

Also, I just noticed this, but when you step on the brake pedal in these cars(observed this on both our 951's, and the 968), the whole brake booster moves, looks to be because of the firewall flexing...wtf? Never noticed this happening on any of our cars, but I was surprised at how much movement there was....


thanks
mike

Mike C.

I'd take a close look at the slave cylinder. If the car sat that long and there was some water in the slave it may be badly corroded.

FRporscheman

The clutch on my '95 has always been ridiculously stiff. I always figured it had the sport PP, but you say yours was fine until after this job. Hmm...

Mike951

Maybe some misunderstanding......

I suspect the stiff pedal may have contributed to the firewall cracking in five places before I bought this vehicle a month ago. Car has 150k miles on it.

Evidently, this condition has been seen by other 968 owners as these cars age.

The firewalls on the 944 series as well as on the 968 look like they could have used a bit more thickness based on my recent observations.

For now, I need to focus on the stiff 968 clutch. Any info is appreciated.

Thanks

Mike951

Bump

PorscheDude1

Check the clutch fork needle bearings. This become stiff if not used. You may have to re grease them.

Mike951

What do you use to grease them? If you clean and regrease them is there some sort of special grease that you need to use?

-Keith

PorscheDude1

Wheel bearing grease. Remove the access cover above the clutch slave, and have someone press on the clutch pedal. Maybe you will see some binding.

marky522

I know its different but on the newer cars when i see this its more due to buildup of clutch dust on the tube that the T/O bearing rides on.

Mark

Luis de Prat

Had this same problem. Besides checking or replacing the clutch hydraulics for leaks, lubrication, etc., what's probably causing the stiffness is that the master cylinder piston is binding due to the firewall repair.

How did you repair the firewall? On my 83 the shop fabricated a reinforcement by riveting a 1/4" thick metal plate with holes for master cylinder and brake booster to the cracked firewall. This changed the geometry of the piston's route through the firewall and the pedal would bind.

I didn't do this myself and it was several years ago, but I do recall there was some grinding involved -I want to think on the piston itself, but it could've been on some other part in the assembly that was causing the binding. Anyway, whatever it was that was grinded down, it brought the pedal back to normal and I never had a single problem with the master cylinder afterwards, except for it leaking again several years later and being replaced without a hitch.

So take a good look in the driver side footwell and see what you can do to change the geometry of the master cylinder as it travels through the firewall.

P.S. pm sent about some parts.