Clutch cylinders problem analyze needed. Please help.

rnln · 10:57 PM

Is it the clutch master cylinder or the slave cylinder?

My tranny need pitty. One night in hell. I need opinions...

We have not been out for a long time before and after my first baby came out. Tonight, the first night we went out, to a friend's welding. It is far and it happen.

For months, my clutch's been having the famous problem of not fully pulled up, therefore I never wear my left shoe when I drive my P. Tonight, after I left home for around 20", I felt my clutch quickly lost pressure, to the point there was not any pressue at all. I could push the clutch all the way in while the gas pedal was in place at around 3k+ RPM without any affect. The clutch pedal is completely light as there was nothing attached to it. I know right away that I lost one of my clutch cylinders (or maybe both).

Driving all night long for around 200+ miles without clutch is a night mare, especially 20+ times of stop and go. Everytime there is a red traffic light or a traffic jammed, my wife hold on to her seat, and I feel hurt in my stomach so bad because I know my tranny will feel the same.

QUESTION:
Do you think my master cylinder is bad, or my slave cylinder is bad? I don't want to shell out the money for both while there is only one goes bad. Or this is something I should do it both since I'm there?

Problem analyze (trying):

If my clutch can fully return but I can't engage the gears, slave cylinder might be bad but the master cylinder is good since the master cylinder is pulling the clutch pedal back up.

Since my car was running in perfect condition and suddently the clutch pedal has no pressure at all (no pressure either when pusshed in and when pulled out). The problem must be the master cylinder. Am I correct?

If I am correct, should I rebuild it (if possible) or I should replace it? Anyone know pricing of rebuild and replace? Is it worth it to rebuild?

Please tell me what you know. Thank you much.

Rick V · 10-08-2006, 03:50 AM

If the slave cylinder has gone you will notice you are loosing fluid in the master cylinder. If the master cylinder is gone you will have the symptons you state but no loss of fluid.
Personally If one goes you need to replace both. With a new unit in the system the pressure it has is enough to rupture the seals in the other unit. Remember both the slave and master have the same amount of use on them.

ianc · 10-08-2006, 10:21 AM

If you're able to fully press the pedal without any pressure or sign that the clutch is engaging, you might have a busted line. Your first and most obvious task is to get the car in the air and inspect the lines and cylinders for leaks and\or breaks.

ianc

rnln · 10-08-2006, 10:48 AM

Thanks for response,
I have not have time to get to the car yet but I did check the fluid reseroir (in the front trunk) and found that the fluid is right at the MIN level. I don't know what exactly it was before this.

ianc,
Yes, there was no pressure AT ALL. When I was driving at 80+ mph and pressing the clutch pedal while the gas pedal is still depressed, there is no affect at all. In fact, I shouldn't say "pressing" because the clutch pedal is very light. I can say the pedal is "free fall" right now.
Where, which area, proximately I should look at to trace the fluid line?

Thanks

ianc · 10-08-2006, 10:56 AM

Quote:

Where, which area, proximately I should look at to trace the fluid line?

Well, the master cylinder lives behind the brake pedal, slave cyl is on top of the tranny. Those would be the first two places to look. Also look for any wetness under the car which might be brake fluid.

A Carrera Bentley would be a good thing to have...

ianc

rnln · 11:29 AM

Ok, so I am correct on where the cylinders palces. I just went out and took all the pedal panels and carpet off to check in there. The area is dried, no fluid, and everything look normal to me. THe pedal is very light as free fall but the little piston rod does move in and out when pushing and pulling the pedal. I guess I have a leak somewhere or either one of the cylinder. I have not jacked the car up yet but the ground and underneatht he car has no leak. I hope it is not something inside the tranny housing broken.
With this symptom, no pressure at all, do you think if there is a posibility of just the fluid is too old/bad/debris? I wouldn't think so but I want to hear opinion.
Thanks.

Rick V · 10-08-2006, 11:32 AM

Quote:

Originally posted by rnln
do you think if there is a posibility of just the fluid is too old/bad/debris?

Not likely, even old fluid will have hydrolic properties. If you have debris in the fliud than you have a componant failure.

ianc · 10-08-2006, 11:52 AM

Yes, even old fluid will still provide pressure. Since you have what appears to be a catastrophic failure, you likely have something broken. Either the slave cyl has come loose from the tranny, you have a broken line, or something's busted in the tranny.

Kind of useless to speculate until you actually get the car up in the air and see what you're dealing with. My guess is that it will be fairly obvious once you're under there,

ianc

rnln · 05:15 PM

Thanks guys. I guess next weekends then.
Can someone tell me what kind of fluid is acceptable for clutch in my 87 carrera?

Rick V · 10-08-2006, 05:15 PM

The same brake fluid you use in the brake system, dot4

rnln · 10-08-2006, 05:16 PM

Thanks Rick.

88911coupe · 10-14-2006, 07:58 PM

Just to add to this...I had a similar problem. My clutch pedal would go all the way to the floor and I'd have to pull it up with my toe. It would disengage the clutch(barelyt) but I'd have to pump it a few times on occasion. I replaced the slave first since everyone said that was the most likely one to go bad. I should note that I NEVER saw any fluid leaking since the fluid was just going past the piston seal and then returning when I let off the clutch. Anyway, replacing the slave did nothing so I ordered the master from Pelican and that solved the problem. It's a major PITA and don't waste time, like I did, trying to replace the slave without a partial engine drop. It's MUCH easier...trust me. Also, there is no way to tell which one is bad, unless of course you see a leak so it's sort of a roll of the dice which one to replace first. The good thing is it's not real expensive to replace both of them, assuming you do it yourself.
Good Luck

rnln · 10-15-2006, 09:23 PM

Thanks Buck