Hi,

I have recently fitted an aftermarket clutch pedal which works really well, the old one was sticky and didnt feel right, however in the past few days I have been experiencing a few issues, mainly with the clutch feeling like it isnt engaging properly, like its slipping.

After a period of time when driving the car hard the revs rise considerably quicker than my speed when I put my foot to the floor and then will drop back again and begin adding power, it feels like the clutch is slipping (from what I know) however I was unsure if it could be due to not having braided stainless clutch lines meaning I am running into problems with the master cylinder not actually engaging the clutch properly in the first place and giving the sensation that it is slipping as it doesn't seem to be happening all the time like I'd imagine a slipping clutch would.

Thanks for any advice in advance

 

Which clutch pedal did you install? Are you driving with your left foot resting on the clutch pedal? Always use the dead pedal when you're not shifting, I've seen some guys driving using the clutch pedal as a footrest, the end result is something similar to what you described. If this is not the case for you, then I would say it might be time for a new clutch. Which year Z do you have? DE or HR? If you have an HR and you're still rolling with the OEM concentric slave cylinder, it could be going out. Either way, the transmission will need to be dropped.

Replacing the clutch pedal by itself does not involve any work to the hydraulics (disconnecting lines, bleeding, etc), so I doubt the new pedal is the root cause. You could try bleeding the clutch hydraulics to see if that makes any kind of difference, but I doubt it will. The clutch pressure plate ensures solid engagement when in gear, if you're getting any kind of slippage during a power pull, you either need a new clutch or, if you have an 07-08, your CSC might be leaking fluid onto the clutch. Fluid on the clutch will cause slipping and ruin the disc at the same time.


Good Luck!
-Icer

 

A slipping clutch doesn't start slipping at all RPM's right away. It's based on torque applied/temperature of clutch disk.
Sound like your clutch is starting to go, so go easy on it if you can't replace right away and you can probably get another 5k miles out of it or so, honestly.

An older slipping clutch has nothing to do with anything except
1) Worn clutch or
2) Pressure plate isn't being released all the way(resting root on pedal like icer said)

Any problems other than that would cause the clutch not to release all the way vs making it slip.

 

Hi, no I actively make sure I keep my foot on the dead pedal when possible but good advice as not many people do!

I have a de revup 2007

I have changed the pedal to an rjm one in order to help this issue however I didnt fix it properly, which is why I may think the fluid is bad as well as the hoses still being standard and expanding with the heat, along with possible cylinder issues.

It feels like the clutch isnt fully engaging once I have been driving the car and while and everything is warm (the fluid and hoses etc..) which may be giving the sensation of a slipping clutch as it does seem to fully engage and bite again properly after a few seconds if that makes any sense

 

To be honest with everyone I just want it sorting so I can get back to really enjoying my car 😂

 

I also have an RJM pedal and they are solid. When you installed it, were you careful about making sure to keep the Master Cylinder lock-nut & rod at the stock location? Also, double check your height adjustment of the pedal. While released and pushed in (during full range of motion), the rod should remain close to being level or parallel with the floor pan. If you have an extreme angle on the rod due to poor adjustment, bad things can happen. (Primarily the master cylinder seals will fail prematurely)

Having overheated clutch fluid or air bubbles in the line should actually have the opposite effect, the clutch would be more difficult to *disengage* from the flywheel.

Since you have a DE, you can try bleeding the fluid. It's a pretty easy process with a buddy to help, but I'm 95%+ certain your clutch is just going out and needs to be replaced. How many miles are on the zed?
-Icer

 

Yeah that makes sense, and I am unaware of how the pedal was installed as I took the old clutch pedal off myself and then took it to a shop to have the RJM pedal fitted as i got called to work away but needed my car as soon as I was back. Is there any way to check the shop fitted it properly as I'm not 100% sure they did the best of jobs. In saying that it does feel fine most of the time and only seems to slip once I really put my foot to the floor in which the revs rapidly climb and the speed doesn't until the clutch seems to fully engage and the revs drop again and begin to act normal until I change gear or put my foot down again. There is just under 90,000 on the clock

 

Email RJM performance. He has detailed print-out instructions for how to set a "same as stock" starting location for the pedal (it may have been included in an email attachment when you placed your order). I would recommend going through this procedure to rule out a poorly adjusted/setup pedal. Actually, I would read through the entire installation procedure. There are good notes and pictures explaining everything about the pedal. From there you can inspect the shop's work and verify everything was done right. With that being said, my money is still on a worn-out clutch disc.
-Icer

 

Icer, that sounds like a good plan, I have just downloaded the pdf files with all instructions for the right hand drive pedal so will go through this all in the coming days and asses what has been done.

I am in 2 minds, one is telling me to just work through the clutch problem possible solution by possible solution and essentially keep chasing the problem, as with the car having 2 previous owners I'm not 100% sure how they maintained it and the garage I bought it from wasnt the most useful afterword, and the other is telling me to just spend a few hundred more pounds to fully redo the clutch system, cylinders rebuilding and all so I know for my own piece of mind that it has been done and will be maintained properly by myself in future, thoughts?

Also I have driven it over 200 miles this weekend and it only seemed to be a problem when I put my foot flat to the floor once the car was warm, at which point the clutch would slip over 3000rpm, I am unaware whether this would happen with a slipping clutch or not? It also only seemed to happen sometimes, there were times when it would hold and carry the revs as it should all the way to 6000rpm, sorry for all the questions, I just dont want to be looking at fixing the wrong thing as I have never experienced a car like this and of this age and would rather ask the questions now than just think I know everything 😂

 

This is all dependent on the amount of torque being applied. Clutches are rated in terms of torque not hp. With the pedal to the metal you're going to put out max torque. I don't know the engineering terms for this, but if the vehicle is already moving at speed (lets say 70kmph), less strain will be put on the clutch when flooring it vs. floored at 25kmph. This is also highly dependent on which gear you're in. A simple test can be done to get a better idea.

From a stop, put the car in 3rd gear and try to launch. If the engine stalls immediately, odds are the clutch is ok. If you see the RPMs shoot up and the car barely moves with the clutch pedal fully released, odds are the clutch is done for. Another way of achieving this test is to attempt the same thing, but going up a hill in 2nd or 3rd gear while applying moderate throttle. Same idea, if the RPMs shoot up, without any acceleration or wheel spin, you got a worn out clutch.

In terms of the clutch hydraulics. If the inside of the clutch fluid reservoir has a black film sticking to it, and the fluid itself is also very dark, then I would (if it was my car) replace the master cylinder and slave cylinder. The OEM parts are cheap/affordable and you would have the peace of mind. Don't fuss with rebuild kits, these often fail and the amount of money you save isn't worth the time taken to do the job twice a few months down the road. Just my 2c.

Good luck! I hope you get it all sorted.
-Icer

 

That sounds like a good idea, I will go out and do the tests, I have just driven it and I dont know if it's my tiredness or something but the clutch just didnt feel right, even more than usual, thanks for all of the advice