JasonAndreas

Use a piece of clear tubing on the slave cylinder and back light it. Then you want to repeatedly open and close the valve until you can no longer see air bubbles coming out. Tapping the unit with a rubber mallet will help to!

Alex Sol

thanks for the pic of the brake fluid overflow 'pinch'. i was pinching in the wrong spot.

i bled the clutch and pushed through about 1/2 litre of fluid and now have pedal pressure but no 'action'. i can press down the clutch pedal about 1 inch then gets totally stiff and does not allow me to engage any of the gears.

i pumped up to 15 psi to try to force some more fluid into the master as it seems to have pressure but no action....

is this supposed to take a long time?

i did damage the slave a few years ago 'bleeding' the system but i think the issue was i did not have the needle bearing in. ended up breaking the mount that holds the shaft for the clutch fork. got it welded back in and it has held for last 75,000 kms without issues...

Vandit

You're sure the slave was positioned correctly during installation and is engaging the clutch fork?

Rocket Rob

Are you sure the slave cylinder rod is in the proper position? Is it pushing on the clutch throw out arm? I was installing my engine last week and the rod got out of position and I almost installed it. Luckily, I had shifted my arm and noticed that it was out of position. I reset the rod back on the throw out arm.

If yours is out of place, the clutch slave hydraulics may be ok but the pedal would feel wrong.

This is just a theory.

Alex Sol

Rob,

That has got to be it... because i have pressure but it feels like i'm pushing against a wall.

Alex Sol

Okay, i found the slave was in fact out of position and blasted into the cavity of the transmission housing

if put it back together first cleaning out the black muck in behind the piston / seal.

Then found a broken rubber boot that protects the guts

replaced the odd shaped 'starburst' washer that holds all the guts and seal in place.

found the slave hose to be in bad shape. purchased new and installed back into place

this time with the slave touching the round groove in the clutch fork

used motive power bleeder and ran thru about 400-500 ml of brake fluid

started up the 964, and clutched in and have no action for the first 1" then a grinding sound and with the clutch to the floor, a more unpleasant grinding sound.

also cannot put any gears in... just seems to rub like when you stick your finger into a fan....

new slave perhaps???

JasonAndreas

Did you lubricate the receiving cup of the release fork with Olista Longtime 3EP?



There should be maybe 1/2" of travel but each master cylinder is different so 1" is not unheard of...

You are probably hearing the release fork rubbing against the clutch pressure plate. There is an adjustable clutch pedal stop on the wooden floor board.



The spec for total pedal travel is (150mm ± 5)




Have somebody operate the pedal while you watch the slave cylinder modulate the release fork. Based on the grinding sound it would seem to be working?

Alex Sol

great advice Jason... will check both!

I did not grease the little hole but i will....

how is the adjustable clutch pedal stop adjusted? back off the hex or torx (can't tell from the pics) and slide vertically up or down?

Alex Sol

greased the hole, installed new slave, replaced the hydraulic hose, bled system with motive bleeder, using Jason's open/close tapping method... still have the exact same grinding issues with the clutch...

just killing me this...

Alex Sol

definitely sounds like clutch fork rubbing against pressure plate.

there is pretty good extension on the slave cylinder... just cant get the clutch to work properly and allow me to get into any gears.

JasonAndreas

What brought this on? Did you replace the clutch and/or flywheel?

Rocket Rob

Is your clutch pedal travel correct? If you its too long, you will get a grinding sensation. Ask me how I know.....

Alex Sol

no i did no replace any of the components.. just new slave and hydraulic hose.

the clutch pedal travel was perfert before.. in fact it would engage/disengage about 1/2" into the push of the pedal...''

grinding... terrible.

i can see the fork pressing against the pressure plate..

is there a spec on the length of the slave cylinder piston

the distance from the fork to the pressure plate is about 1" or even less

could i have put the clutch and flywheel together incorrectly? there were only about four pieces...

flywheel to crank- all new studs - torqued to spec
clutch in loose (with alignment tool)
pressure plate to flywheel - - all new studs torqued to spec.
fork (with painter's tape)
shaft to hold the fork...







or missing a spacer or something like this.

Alex Sol

is it possible the fork is not angled properly due to mis alignment with the center of the pressure plate?

i have a pic of the flywheel that looks like it is sticking out too far... please review...

Rocket Rob

Alex - Does the grinding sound happen during the whole stroke of the pedal or just at the bottom? When my travel was too long, mine was perfect for 90-95% of the travel. It only made a grinding noise at the bottom of the pedal travel.