Heavy clutch pedal

[enrico]

Looks like I am starting off a 3rd clutch today after just 11k miles (all of them stock), I got it installed with brand new flywheel and slave (came out to an exhorbitant amount of money all-in, probably 'cause I am in the uk).

Reason for the post is that unfortunately I am a bit frustrated with pedal feel... quite heavy (compared to other GTs I have driven) and definitely on/off. It was the case previously and guess the reason for quick wear, i.e. havent done any burnout or 3rd gear hill start ever!

I would have thought that replacing slave and flywheel should have gotten me a brand new feeling but I am now doubting this, my car is an early 05, are there any other parts (e.g. cables/wires) that can be responsible for this in your expert view?

Many thanks in advance for any insight....

 

[nota4re]

Hi enrico. Sorry for the trouble you are having. We have done numerous clutch/flywheel installs and I can't think of anything that is too tricky about them. I think you are doing the right thing to replace the flywheel and the throw-out bearing at the same time. For what it's worth, we really like the SPEC clutch and flywheel over the OEM unit and I think the price is about the same - maybe even a little bit less for the SPEC unit. Make sure the clutch is bled well after the install. I hope this is your last clutch for a long time!

 

[Kayvan]

Can you describe how you drive your clutch:

-Do you give gas to start off OR
-DO you let RPMs of engine engage and roll off with no gas
-Do you ever smell acrid / burnt smell in cabin
-Do you keep clutch pedal depressed while coasting or to hold inclines/stops
-What does ur clutch fluid look like?

Seems like obvious quesations...however, after 15yrs with a '85 BMW M6 clutch I found my clutch driving skills were not the greatest. After getting a '12 Vette, I found unless you can feather the clutch at exact rev match then you will get clatter, chatter, & shudder. If you feel any of that and are giving it gas to overcome then you are glazing your clutch and it will wear out prematurely.

Would try driving other friends clutches...esp Porsche or Ferrari and see how they critique your engagement technique.

ps, Heavy or spongy feel is usually b/c of air or contaminated fluid in system....check entire line as a leak could cause this

 

[Xcentric]

To echo Kayvan's first two points, there is really no need to slip the clutch when starting. The engine control will keep the engine from stalling. Slip while moving from a stop would be the primary cause of wear. Resting your foot on the clutch pedal between shifts could be another.

As to heaviness and on/off switch, I can only speculate. Incorrect parts perhaps. The clutch action is BMW smooth and light. Really remarkable considering the torque it must handle.

I will be surprised if I ever have to get a new clutch.

Sorry to hear about your problems. Clutch failure that early is extremely unusual.

 

[enrico]

Thanks guys for the replies... On driving style I can take the blame, not sure to being the best clutch driver tbh. From a standstill I usually modulate throttle (very little) to avoid stalling while not slipping. Would you be suggesting not to appal throttle at all? When I do so car does not stall but rpms drop substantially and it doesn't feel good to me. Don't hold the car on hill or press when coasting either....

I have put many miles on a Ferrari and a caterham w/o having such a clutch wear but probably not comparable with aspirated less torquey engines... And their pedal feels lighter which makes the job easier!

Will check with mountune if they have bled the system but I would guess they have done so.

 

[Kayvan]

Give it ZERO gas

A GT can go up a 45 degree hill (from dead stop) with zero gas

Just watch where that needle blips up when the clutch bites...your leg muscle memory will become 2nd nature and you wont need gas

A GT can literaly roll at 3-5mph with out stalling on level ground.

Some folks here know how to do "power shifts" at high RPM/speeds in 4-5-6 gears to smooth out a clutch plate that has glazing or rough spots...maybe that will help too

 

[mmlcobra]

Hey Enrico,
Sorry to hear about your problem.
Clearly, something is wrong here.
As stated above, wrong parts selection, wrong install,wrong bleeding procedure, must be suspected.
Many people have put many miles on the stock clutch, including many high horsepower mods such as Whipples and TT's.
Hope you find the solution soon.
Best,
Mark

 

[enrico]

Give it ZERO gas

A GT can go up a 45 degree hill (from dead stop) with zero gas

Just watch where that needle blips up when the clutch bites...your leg muscle memory will become 2nd nature and you wont need gas

A GT can literaly roll at 3-5mph with out stalling on level ground.

Some folks here know how to do "power shifts" at high RPM/speeds in 4-5-6 gears to smooth out a clutch plate that has glazing or rough spots...maybe that will help too

Thanks for the advice, actually my tach blips "down" when the clutch bite (unless I release clutch very slowly and then there is no blip whatsoever). I am actually applying gas at that point in order to prevent that... Maybe that is confusing the stall system then? Btw a straight pipe exhaust would have an impact on the antistall??

Having said that seems that pedal being heavy can only be a function of air in the system? Are there any other mechanical parts that can be responsible? Other than slave etc which is new??

 

[fjpikul]

Did they totally replace the clutch fluid? It will turn to jelly over time and with contamination. There are two bleeding points: one on the firewall about center of the cabin, and one down low on the passeneger side. Don't bleed whne the engine is hot cause both areas are a little hard to get to and harder when the engine is hot.

 

[enrico]

Did they totally replace the clutch fluid? It will turn to jelly over time and with contamination. There are two bleeding points: one on the firewall about center of the cabin, and one down low on the passeneger side. Don't bleed whne the engine is hot cause both areas are a little hard to get to and harder when the engine is hot.

Would have hoped so, I'll check again!
In case they haven't would I be able to do it myself or does it need to go back to garage?

 

[Kingman]

Motive - http://www.youtube.com/watch?v=QSDQCAXxkh8

 

[BlackICE]

Motive - http://www.youtube.com/watch?v=QSDQCAXxkh8

I have one of those with many adapters. I have done my FGT brakes with it works great. On my Chevy pickup I used it on the clutch and for some reason it didn't work well and I had to manually bleed it. I didn't do the FGT clutch yet so don't know how well it works there.

I have only one concern, it is under pressure and if anything leaks, brake fluid will damage paint. So cover up anything you think may be at risk and keep a supply of water around to rinse it off quick just in case.

 

[Howard]

The video shows the Motive Bleeder being used per the Motive instructions. Many users, including me, prefer to use the container without brake fluid; using it only as a source of pressurized air. This method has the advantage of being much easier to disengage the Motive Bleeder from the reservoir without spilling brake fluid, and the reservoir doesn't fill to its brim with fluid. The obvious downside is that you must monitor the level of fluid remaining in the reservoir during bleeding to assure that the reservoir doesn't run out of fluid and ingest air into the brake (or clutch) lines.

Howard

 

[BlackICE]

If you start off with the reservoir only 20% or so full it doesn't fill up to the brim causing a mess.

 

[nota4re]

Having done dozens of Ford GT clutch bleeds, I would definitely NOT recommend this tool for this application (although perhaps a great tool for other applications). The Ford GT clutch reservoir has the smallest capacity of any that I have worked with. The opportunity to make a mess compared to a traditional 2-person pump and bleed method, simply favors this later method. I do, however, have a tip. For the person in the car, it is best to be barefoot. When bleeding the clutch, the pedal NEVER comes back up on its own and it's easy to bring it back up if you "grab it" with your toes.

 

[FENZO]

Having done dozens of Ford GT clutch bleeds, I would definitely NOT recommend this tool for this application (although perhaps a great tool for other applications). The Ford GT clutch reservoir has the smallest capacity of any that I have worked with. The opportunity to make a mess compared to a traditional 2-person pump and bleed method, simply favors this later method. I do, however, have a tip. For the person in the car, it is best to be barefoot. When bleeding the clutch, the pedal NEVER comes back up on its own and it's easy to bring it back up if you "grab it" with your toes.

My experience exactly. We found it to be best to get on the floor and pump/hold/pull the pedal with your hand. The qty is so slight that you can move several times the capacity through the system in short duration.

 

[Kingman]

Having done dozens of Ford GT clutch bleeds, I would definitely NOT recommend this tool for this application (although perhaps a great tool for other applications). The Ford GT clutch reservoir has the smallest capacity of any that I have worked with. The opportunity to make a mess compared to a traditional 2-person pump and bleed method, simply favors this later method. I do, however, have a tip. For the person in the car, it is best to be barefoot. When bleeding the clutch, the pedal NEVER comes back up on its own and it's easy to bring it back up if you "grab it" with your toes.

OK................I'm all ears! What are the recommended tools and procedure?

 

[mopar]

never have your foot on the gas and clutch at the same time

 

[nota4re]

OK................I'm all ears! What are the recommended tools and procedure?

It's really a pretty straightforward process. With clamshell open and 10mm box end wrench in hand, lean over the passenger side rear tire and find the clutch bleed nipple. Pull the rubber cap off, put the box end wrench onto the hex portion of the bleed nipple and attach a length of vacuum hose onto the nipple and route the other end into a container. Have another person sitting in the car, barefoot! (LOL)

On a lot of cars, our intent is to flush out the old (often goopy) fluid. In this scenario, we use a syringe to suck the fluid out of the master cylinder reservoir. Get all of the old fluid out and then fill it with a fresh fluid. (We use Motul.) Fill the reservoir to the top.

Bleed procedure:

1. Person in the car pumps the clutch pedal 2-3 times and then holds the clutch to the floor.
2. Second person opens bleed screw momentarily and then closes. A small amount of fluid will squirt out.
3. Person in car will need to lift clutch pedal with toes and then repeat steps above.

Note: The clutch reservoir is SMALL. After only three openings of the bleed screw, check and re-fill the level in the reservoir.

To be thorough, you can do this process to draw the new fluid in and through the system. It will take about 12-15 openings of the bleed screw and then you are done. Pretty easy but just don't forget to keep checking the level in the reservoir. To be honest, when possible we use a third person whose only task is to keep the reservoir full throughout this process.

 

[Kingman]

Thank you for your consideration Kendall.