Cluthc gone. Tips appreciated

[Beirut944]

My clutch has just suddenly lost all of its hydraulic pressure. Absolutely no resistance at all. I was wondering if there was a simple and quick method of identifying which of the two cylinders it could be. There is no leakage of hydraulic fluid and it is still at the level in the reservoir.

Lat year i overhauled both cylinders and replaced all of the rubber hydraulic rings. They were not original parts though and i guess i am paying the price now for being stingy. But first i need to know is it up or down?

thanks

Any advice appreciated.

[rufrob]

Could have gotten air in the line due to low brake fluid. Bleed. Or Power bleed!!


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[944 Ecology]

Most likely the lower one, since dirt can accumulate there are damage the seal. Replace the lower one first, and, if that doesn't solve the problem, replace the upper one (which is a lot harder to do.)

[v2rocket_aka944]

jeez, you just cant win with this car.
while you are inspecting the slave (lower) cylinder take a look inside the bellhousing and make sure the clutch fork is still hooked up...

[Beirut944]

Originally Posted by v2rocket_aka944

jeez, you just cant win with this car.
while you are inspecting the slave (lower) cylinder take a look inside the bellhousing and make sure the clutch fork is still hooked up...

THat made me laugh. Well done. But jokes aside, is it possible that the rod sticking in could actually have dislocated itself from the bellhousing?

I actually fitted it myself a year ago lying on my bank in the road in an Arab country. Quite something, i can tell you.

The wisdom seems to point to start with the slave cylinder first. But with someone else pumping the clutch how can you identify if it (the slave) is the problem or the master. It's not obvious.

MJ

[kevingross]

If you have clutch fluid on the garage floor, it's the slave. If you have fluid on the driver carpets, it's the master. Regardless, it makes decent sense to replace both as well as the plumbing, if they're original or dated. Good luck!

[9FF]

Originally Posted by kevingross

If you have clutch fluid on the garage floor, it's the slave. If you have fluid on the driver carpets, it's the master. Regardless, it makes decent sense to replace both as well as the plumbing*, if they're original or dated. Good luck!

*The line between to master and slave and the blue pipe from the reservoir to the master.

[Beirut944]

daer all
Update. I whipped off the slave cylinder as when i got under the car it seemed that there was some oil around the area where it joins the bell housing. Also, there was some oil on the outer rim of the start motor.

BUt there was something weird. When i disconnected the hydraulic line going into the slave itself, no hydraulic fluid came out. Is this normal? I'm guessing that there is no easy way for air to escape so it hangs in the system. If i' wrong and it should piss out, then probably the problem was air in the system.
Looking at the slave itself, i noticed it was extended, which also confused me.

All comments, even piss taking, welcome. Yes, i'm a Brit in Lebaonon with a NA 944 with no AC. It's hilarious, i know. And also no clutch now.

If someone can tell me what the roadside test is for the slave, to check whether it functions correctly or not, i would be very grateful. There must be a 'shade tree' way of testing it on the bench. Please let me know.

If it's my slave then the lesson i can share with all of you is don't bother with after market rubber seals as this is the weakest link in my case.

thanks

MJ

[djnolan]

One way to bleed the system is to use an old pump style oil can filled with brake fluid and a hose to the slave bleed screw. Open the bleeder and pumping fluid upwards pushes the air out.

Here is a rebuild instruction: http://www.944online.com/pdf/944slaverebuild.pdf

It is pretty simple, just a piston seal and a dust boot. If it is scoured then it might need to be replaced. Don't use anything abrasive to clean it, use a green scrub pad.

[Beirut944]

Originally Posted by djnolan

One way to bleed the system is to use an old pump style oil can filled with brake fluid and a hose to the slave bleed screw. Open the bleeder and pumping fluid upwards pushes the air out.

Here is a rebuild instruction: http://www.944online.com/pdf/944slaverebuild.pdf

It is pretty simple, just a piston seal and a dust boot. If it is scoured then it might need to be replaced. Don't use anything abrasive to clean it, use a green scrub pad.

Useful tip. When i did it the 1st time i did it the other way aruound, from top to bottom. BUt with the slave way how do you know when you're done?

MJ

[djnolan]

If you fill the oil can it should be more than enough to push all of the air out. It is nearly impossible to bleed by pumping the pedal. A power bleeder is your only other option. Is the fluid on the bell housing brake fluid or something else?

Even if you bleed it as described, If you have a badly worn slave cylinder it will eventually allow air to get in the system. I would bleed and see how long it lasts if you have already rebuilt the slave. Maybe it wasn't bled fully to begin with..

[Beirut944]

Originally Posted by djnolan

If you fill the oil can it should be more than enough to push all of the air out. It is nearly impossible to bleed by pumping the pedal. A power bleeder is your only other option. Is the fluid on the bell housing brake fluid or something else?

Even if you bleed it as described, If you have a badly worn slave cylinder it will eventually allow air to get in the system. I would bleed and see how long it lasts if you have already rebuilt the slave. Maybe it wasn't bled fully to begin with..

Cryptic questions indeed. YOU may well be right. It might not have been bled properly in the first place. But there was some oil. I can't know for sure if it was hydraulic or sump.

I wish there was a simple way of testing the slave on teh bench. If you have an idea of what is a good benchmark, let me know. My instinct tells me that the ring seal is still good and holding.


MJ

[Beirut944]

Can anybody tell me if its normal to remove the hydraulic line into the slave and no fluid to drop out?

thanks


MJ

[flash968]

lol - i appreciate my 968 tip when i drive it too. having the clutch gone is much easier in traffic.

sorry guys. couldn't pass that one up.

[thomasryan]

you could shove a deep well socket behind the fork at the inspection hole to see if your issue is hydraulic or mechanical

[Beirut944]

Originally Posted by thomasryan

you could shove a deep well socket behind the fork at the inspection hole to see if your issue is hydraulic or mechanical

The "fork"? Can you please explain in more simple terms. The inspction hole being the one you look into from leaning over into the engine from above?

[thomasryan]

from below. there should be a circular plug where the slave pushes on the clutch fork under the car on the bell housing.

in theory, if you stop the slave pin from extending and your seals are good, the clutch pedal in the car will not move to the floor.

[Bradical]

Originally Posted by Beirut944

Can anybody tell me if its normal to remove the hydraulic line into the slave and no fluid to drop out?

thanks


MJ

If the cap is on the brake fluid reservoir was on, it could prevent fluid from running out of the tube because of the syphon effect...

But, I am guessing there is no fluid in the tube, it has all leaked out. The brake fluid resevoir has a chamber in it that prevents the fluid for the brakes from draining out in the event of a clutch failure- so the clutch hydraulics can be completely dry but with enough fluid in the brake resevoir for it to appear nearly full. I think this is your situation.

Thats actually the cause of the majority of the headaches to people performing the clutch bleed- you dont notice that you've drained down that channel in the brake resevoir and you pump air bubbles in again and again. You have to keep the resevoir absolutely full as you go and it becomes very easy.

[flash968]

this is why everyone should use a motive power bleeder. no pumping air into the system.

[Bradical]

Originally Posted by flash968

this is why everyone should use a motive power bleeder. no pumping air into the system.

Certainly makes the job easier- and takes half as many people.