Weird Clutch Problem – Advice needed

Coming home last night I was driving the car quite hard and suddenly when I depressed the clutch pedal to change gear it would only go half way. The next time I pressed the pedal it was normal. Then a few gear changes later it did it again. I slowed down and drove the car really gently the rest of the way home with minimal gear changes and it all felt fine. The clutch operated normally and felt normal.

 

Usually my clutch pedal will depress all the way to the floor/bulkhead. When this problem happened it felt as if there was a brick under the pedal – it went half way and stopped absolutely solid.

 

I’ve checked the clutch fluid and that’s fine. I’ve had a play with the pedal by hand and can’t find a problem. Later I hope to have time to have a good look above the pedal under the dashboard.

 

Has anybody had this issue before or have any suggestions what could be causing it?

 

Thanks

 

TSS

 

Have you checked the hoses from the hydraulic reservoir?

Have you checked the hoses from the hydraulic reservoir?

 

Not yet, is there anything specific on the hoses I need to check?

Not yet, is there anything specific on the hoses I need to check?

maybe a hairline slit.

 

 

I assume you cannot recreate the problem at will. The clutch system is very simple. In theory there could be something binding in the pedal to clutch master cylinder mechanism under the dashboard but I struggle to think of what it could be. You can check with a flashlight.

 

Mind you, your description of a brick makes me think you may have had something rolling around on your floor in the dark. I once read about a 928 used as a daily grocery getter that went to a track day where a can of soup rolled from under the seat and wedged under the brake pedal at the worst possible moment. Do you get groceries in your Countach?

 

Once the plunger pushes into the master the fluid has to go somewhere, it pushes out the piston and rod of the slave cylinder. A leak would make it depress more easily, not make it lock up. So what is keeping the slave cylinder piston from moving? Is the reservoir still reasonably full?

 

I shudder to think, but could the clutch throw out bearing be binding on the mainshaft? Or the clutch control arm be seizing it its bearings inside the transmission bellhousing? No easy way to tell, but I hope that is not the issue.

 

Look for the can of soup on the floor first.

 

I assume you cannot recreate the problem at will. The clutch system is very simple. In theory there could be something binding in the pedal to clutch master cylinder mechanism under the dashboard but I struggle to think of what it could be. You can check with a flashlight.

 

Mind you, your description of a brick makes me think you may have had something rolling around on your floor in the dark. I once read about a 928 used as a daily grocery getter that went to a track day where a can of soup rolled from under the seat and wedged under the brake pedal at the worst possible moment. Do you get groceries in your Countach?

 

Once the plunger pushes into the master the fluid has to go somewhere, it pushes out the piston and rod of the slave cylinder. A leak would make it depress more easily, not make it lock up. So what is keeping the slave cylinder piston from moving? Is the reservoir still reasonably full?

 

I shudder to think, but could the clutch throw out bearing be binding on the mainshaft? Or the clutch control arm be seizing it its bearings inside the transmission bellhousing? No easy way to tell, but I hope that is not the issue.

 

Look for the can of soup on the floor first.

 

I can’t recreate it at will and it only did it twice but it wasn’t a nice feeling. It really felt as if there was something rock solid under the pedal. However there was no accompanying sound as if the pedal was actually hitting anything.

 

The reservoir on the Master cylinder is full so no problems there. Is there a reservoir on the slave cylinder as well?

 

I do sometimes get groceries in my Countach but I put them in the boot :-) I’ll do another “can of soup inspection” later but I couldn’t find anything in the footwell last night. So I need to get under the dashboard and have a look around the pedal mechanism.

 

Do you know if any of the mechanism near the actual clutch visible from the engine bay or under the car?

 

Thanks

 

I agree that it sounds like it might be hanging up on something. A leak would give you no clutch pedal(loss of pressure). Check the clutch lever and shaft by the slave cylinder and make sure nothing binding.

Hate to say It but it sounds like the throw out bearing to me, and I have a lot of experience of those !!

Hate to say It but it sounds like the throw out bearing to me, and I have a lot of experience of those !!

 

 

Hi terryjoint,

 

Did you get the same symtpoms with your TOB problems?

I’ve just spent an hour crawling about the car. There is no tin of soup or anything else that could be getting stuck under the pedal. The pedal mechanism all seems tight and together with nothing in the vicinity which could jam it.

 

The slave cylinder mechanism seems good too - I used a remote camera to see what that was doing while I sat in the driver’s seat and depressed the clutch.

 

I must have pressed the clutch pedal about 30 times whilst I was looking at everything and it felt normal every time. I’m going to have to take the car out again and see if I can replicate the problem. Hopefully I won’t be able to!

 

Does anybody know if it’s possible to see inside the bell housing with a borescope or something?

 

I’ve just spent an hour crawling about the car. There is no tin of soup or anything else that could be getting stuck under the pedal. The pedal mechanism all seems tight and together with nothing in the vicinity which could jam it.

 

The slave cylinder mechanism seems good too - I used a remote camera to see what that was doing while I sat in the driver’s seat and depressed the clutch.

 

I must have pressed the clutch pedal about 30 times whilst I was looking at everything and it felt normal every time. I’m going to have to take the car out again and see if I can replicate the problem. Hopefully I won’t be able to!

 

Does anybody know if it’s possible to see inside the bell housing with a borescope or something?

 

Yes there is an access hole to do a visual inspection of the T/O bearing area.

 

I would recomend getting the car in the air and have someone depress the clutch while you watch what is going on from underneath.

 

Good luck, Vic

Yes there is an access hole to do a visual inspection of the T/O bearing area.

 

I would recomend getting the car in the air and have someone depress the clutch while you watch what is going on from underneath.

 

Good luck, Vic

 

Thanks Vic. Looks like I need to call my local friendly garage and borrow thier ramp.

One other thing, I assume your car is RHD?

 

Does your car still has the clutch master on the left side of the car, but the brake booster and brake master cylinder on the right?

 

If so, look at the rod from right to left that connects one side to the other. Anything strange going on there? I enclose a diagram.

 

Hi johnmh, thanks for the diagram. My car is a RHD Anniversary and the master cylinders for the clutch and the brakes are both on the RH side as well so linkage is direct. I think they changed this on the Anniversary model whereas previous models had a connection rod system.

 

Anyway, I took it down to a local garage just now who have a some experience on Ferrari’s, Porches, etc. We had a good look at the throw out bearing with a borescope and that all looked good, as did the hydraulic system. We’re 95% sure the problem is the Clutch Return Spring (part no. 61 on the diagram) has broken or become disconnected and is moving around and intermittently jamming the pedal. From what we could see it didn’t seem to be properly attached to the pedal assembly.

 

So quite a relief it that it probably isn’t anything more serious and should cost much to fix! Thanks everybody for your help and ideas.

 

A few years back on my QV when pulling out of the garage I depressed the clutch and heard a "snap". I also found a little piece of metal on my rug. The clutch worked fine, but the return was "sloppy". I had snapped the return spring. It was a 25 Euro part and the install was fairly simple.

My Diablo did this exact thing and it was the hose down by the slave cylinder. It had collapsed internally and was blocked.