Stubborn Porsche Clutch stays down!

2rich2thin · 08-20-2013, 09:09 PM

Hi Forum
1999 Porsche Carrera with 3.4 watercooled boxer 6 cylinder engine non turbo with 6 speed manual.
Okay guys this car is making monkeys out of we two mechanics. The clutch was supposedly working fine before we changed the headgaskets. Thanks for the previous advice, as we'd used too much sealant on the valve covers and were blowing out the rubber cam seals. Redid the job with sealant applied thin and careful and all is well with the engine now.
Now its the clutch. We tried bleeding with the clutch pedal down without the pressure bleeder. The slave cylinder had been disconnected when we pulled the engine DOH! A no no - yes. So we tried bleeding it at the slave, then reverse bleeding it through a the left rear wheel brake cylinder, but the darn pedal would stay at the floor. So we went online and purchased the Motive pressure bleeder, pumped it up to 22 psi and it worked. The clutch pedal was staying up. Then we disconnected the pressure bleeder and "thunk" the pedal wants to stay at the floor. If you pump it up the pedal it will disengage for a while but within a few minutes of standing still the clutch will stay at the floor again! We think there must still be a bubble. It's not leaking. It'll hold 22 PSI all day. We jacked up the rear so its higher than the fluid res but no good. WE actually removed the clutch assy to inspect it for bad pressure plte, and its all fine! Out of ideas. HELP! it's driving us sane.

onewhippedpuppy · 08-21-2013, 05:47 AM

Did you bleed the entire system? The clutch shares the fluid and reservoir with the brakes, if you had the system open you probably have air throughout. What you are describing sounds like air in the system. If it were me I would thoroughly bleed the entire braking system and do the clutch slave last. Pump the clutch pedal as you are bleeding the slave to help dislodge stubborn bubbles. Do it all with the Motive bleeder so you won't be back in the same boat again.

2rich2thin · 08-21-2013, 08:56 AM

No we didn't touch the brakes except for that reverse bleeding trick where we tightened a hose between the slave bleeder and the left rear brake bleeder, cracking the wheel bleeder. I 'd read about it on another site. Didnt solve the problem.
Anyway I understand that the brakes and clutch share the same fluid reservoir, however each system is closed to the other my the seperate master cylinders and lines.
It's worth a try though. Thanks for your input.

jwetering · jwetering's Garage

FWIW - I replaced my clutch and the slave cylinder last year and fought a long time to get the pedal to behave normally. I bled the ***** out of it too, but I had to pull the clutch pedal up with my toes. Once once past the helper spring fulcrum it would pop up by itself though....and importantly when I drove it the clutch would engage and disengage just fine.

Long story short...I drove it like that because I had to but within just a few miles it began behaving normally and after that it has kept on feeling great.

A bit different experience sine I installed a new clutch and flywheel - but maybe just drive it and let it seat?