V8 Vantage Clutch Pedal
 

Yesterday I want to take a drive and the clutch pedal stayed at the bottom.
I had to pull it up by hand.
If I release the pedal quickly it comes back, but under a controlled release I just stayed down.
I do not know if the hinge is dry or could the release bearing is sticky?
It does fully disengage the box and the gear changes is quiet.

I did the double clutch conversion in June and have driven about 3000km.

Any previous problems, from owners. I will bleed it again later this week.

Thank You for any ideas?

Regards

I remember early on there was a recall on the pedals I believe from defects on the Chinese supplier

That was for the throttle pedal.

The most likely cause is large amounts of air in the clutch system, you see any leaks or do any work on the clutch system lately?


The pressure plate springs push on the slave, which hydraulically pushes back the clutch pedal, just not in a smooth motion. So there's 2 tension springs to not rattle when released at top and bottom, also to make a smooth movement, you could always stick your head under the dash and make sure the springs are good. If the hinge is seized/stiff, it would have to create such a bind that it's stronger than these tension springs and clutch pressure plate springs...that's unless the clutch pressure plate isn't pressed the slave due to air, then these tensions springs won't bring the pedal back once at the floor.

I am going to bleed it again tonight and see! Otherwise I will have to strip out the master cylinder and maybe hone it. If not the problem I will have to drop the gearbox and look at the Slave cylinder.

https://cimg1.ibsrv.net/gimg/www.6sp...32a6880d05.jpg
You may want to check the master cylinder attachment at the pedal. It's made of a composite material that can break.

Hallo J

I will check, Thank You. i did bleed about 200ml of fluid through it last night and it is still stuck.

Regards

Look under the dash where the clutch arm pivots. Should be a return spring up there somewhere. Shoot some penetrating oil up there and see if that helps.

I would think the release bearing would have to have something wrong with it to be sticking to the point where the pressure plate couldn't force it back into position. And if when you pull the pedal back up by hand the clutch disengages then that would seem to indicate the bearing isn't sticking. I would think air in the system like others, but you say you've bled it. Are you bleeding it at the slave? Maybe get under the car and see how the slave cylinder is working when somebody pushes the clutch.

Hallo David

You can not see the slave under the car. It is new I installed it in June. I also did squirt some penetrating oil on the hinge bushes. It seemed to work but after 10 minutes it stayed down again. If I partially push the lever down it works it drives, smooth changes in all the gears. So I do not think it is the slave cylinder/ release bearing. I did also looked at the old one the clearance is big between the sleeve and the bearing.

After some time of thinking it over I think the problem could be that the 2 cup seals or the one way valve could be bypassing. I have no fluid loss. It is also very unlikely that the volume in the slave cylinder is more than that of the old one. Meaning that the slave take all the fluid in one cycle and that the pressure drop is enough not to return the slave. The reason I say this is because it did work for 4 months.

I did strip it out! What a job. Photos and explanations to follow. The cylinder is smooth and shiny no ridges,the piston seems to be fine. I will now replace the cup seals. If all else fail I will order a new Master cylinder.

Will keep you all posted. Thank you for all the ideas and comments.

Regards

Kobus

My findings on the clutch pedal that refuse to return.
This was a major undertaking. To get to the pedal box I removed the seat.
The place is small.Firstly I put down plenty paper around the master cylinder and fluid reservoir. Then I removed the pipe feeding the clutch master cylinder. Then installed a similar pipe to the outlet this pipe was about 300mm long. I cable tied it to the cross brace in the engine bay. This is to prevent all the liquid from draining. I drained the clutch from the bottom. (slave cylinder)
Then I took off the 2 nuts under the dash.
Remove the pipe that feed the slave. then cover the slave with paper. Not to spray fluid all over the engine. Went back into my hole remove the clip form the pedal.
Back to the engine side and pull the master cylinder off. In this case easier said than done. There is a metal plate against the firewall and the oval aperture has moved probably during building the car. The master cylinder flange was now stuck behind this plate. I then took a pipe and pushed it over the m/c. Then lifted the rear and pulled. It came out.
It will not go back in and I had to get my Dremel to the plate to open it enough to enable refitting the M/C.

On inspection there were nothing wrong with the M/C. All clean and smooth. I only have 36000 km on the car.

Went back into my hole and spray internal bearing lubricant on the pedal bush. I also took a small tube and a syringe with silicon oil to lubricate the bush.

Installed every thing Bleed the system. And it is still stuck to the bottom of the firewall.

This took me a good 5 hours.

I packed up for the evening and came back on saturday. I still needed to fit the door gas struts. Got into the car and the clutch was popping back up to the original spot.
Maybe the overnight standing gave the oil time to enter the bush properly.


https://cimg6.ibsrv.net/gimg/www.6sp...8976c8d0c2.jpg



https://cimg7.ibsrv.net/gimg/www.6sp...3f9a34ca64.jpg

The clip on the master.

Note the plate behind the heat shield.To get a Dremel to it was an exercise.

Well that must have been a pleasant surprise the next morning

Well done and thanks for the write up

Graeme

Thanks for the explanation. This started happening after you replaced the clutch? Maybe the travel on the new slave cylinder is different for some reason and the pedal needed a little adjustment? Glad it's working now.

Short Lived Joy!
 

The clutch pedal did stick again Yesterday morning!
So now this is it!!

The clutch is coming out. I need to see what it is. I will evaluate and may be put the old Slave cylinder back in.

I will measure the travel before I strip it out and measure the old Slave travel and make a call from there.

There is a noise, like a door hinge that is dry!, when i cycle the clutch.

Will open it up maybe next Friday when the shop is less busy.

Will keep you all posted.

That sucks. Too bad they didn't put some sort of viewing hole in the torque tube so you could at least see the slave in action.