Clutch Travel.

[G_Reaper 170]

Hi

Does anyone know or can anyone measure the distance their slave cylinder moves the clutch actuating arm when the pedal is pressed to the floor.

I have an S4s so anyone with an S4, S4s, or S300 should be able to do this.

Cheers Mike

[sailorbob 264]

According to the service notes the slave cylinder pushrod travel is:

S4 - 17.0 to 18.5mm

S4S & S300 - 18.5 to 19.5mm

[lotus4s 24]

Mike,

Why do you ask?

[CHANGES 1,191]

The length of the push rod is a standard part, once fitted the clutch should be adjusted in accordance with service guide lines. I can not stress how important this is, a poorly set clutch mechanism can cause poor gear change and premature failure. The first spoils your driving fun the second your bank balance. This adjustment is at the master cylinder , this will goven the travel of the arm you refer too. The slave cylinder end is set according to service notes and self adjusts with clutch wear.

Hope this is of help

Dave

Edited August 3, 2010 by CHANGES

[G_Reaper 170]

I only asked because I was getting clutch drag from a brand new uprated clutch I was trying to find out how much movement it would take to release the clutch on other cars as I suspect the new clutch is faulty not my hydraulics. The problem is still ongoing.....

Cheers Mike

[red vtec 185]

I have just replaced Slave and master seals on the clutch cylinders, Should I now look at adjusting the clutch rod? as I'm sure its out of spec, or is best left alone? i.e it it ain't broke don't fix it

Ta

[CHANGES 1,191]

If the peddle setting was correct before it should not of changed, but as it only takes a minute to check, check it....as per sevice notes.....worth doing time to time ...

[Rich H 4]

Bit of a related question, my clutch pedal seems to have 3 distinct stages and I'm wondering if I bugered up my MC rebuild....

The top bit is clearly free play (first ~10% movement)

The next bit feels squdgy as if it's compressing something but it doesn't seem to do anything (it's been bled loads with a pressure bleeder.) (middle ~40% movement)

The last part is the heavy bit. (last ~50% movement)

Also the bite point is very low but I assume this is a combination of skimmed flywheel and new clutch.

Any thoughts? Is this normal?

I did read abotu fitting an SE clutch MC (Smaller bore = longer pedal but less effort) anyone got any details? (I've had a search and only found references to it)

Ta

Rich

[stevem 2]

If you pump the clutch pedal a couple of times does it get firmer in the middle 40%, or still squidgy ?

[Rich H 4]

Still squdgy

[Simon350S 192]

The middle 40% of me is a little squidgy. I know it doesn't help you but just seemed relevant at the time of writing

[Rich H 4]

[DanR 69]

I only asked because I was getting clutch drag from a brand new uprated clutch I was trying to find out how much movement it would take to release the clutch on other cars as I suspect the new clutch is faulty not my hydraulics. The problem is still ongoing.....

Cheers Mike

With your modified set-up you may need to go back to basics. Check on a slope the point at which your clutch disengages. Mark the bellhousing and once you know that the rest should be easy to work out. It's also critical to avoid excessive throw-out bearing travel. Over-extending the diaphragm fingers can fatigue and break them.

[G_Reaper 170]

Thanks for the reply. I have now removed the clutch flywheel etc after approx 70 miles since fitment.

The problem is still unknown, however it was impossible to get the clutch fully disengaged. When removed it was evident the clutch was only contacting the newly machined flywheel for apprpx 15mm of the friction surface on the outer part of the driven plate ,flywheel and clutch cover.

All parets returned to the supplier. Awaiting there response.

Cheers Mike

[Rich H 4]

Strange that you couldn't get it to disengage yet it wasn't fully clamped.

Was the flywheel friction surface blanchard ground?

What clutch is this is it a Valeo or LUK clutch?

[DanR 69]

If the same problem occurs when you get it back make a threaded push-rod assembly. That way you can eliminate the hydraulics while you ascertain the break point.

[G_Reaper 170]

I think the problem was a combination of the fly wheel not being machined correctly flat, and also I do feel as if this supplier was using me as a test bed for his uprated Valeo clutch parts. i.e. bigger driven plate than standard. Maybe I am just being cynical but in hind sight how many suppliers ask you to forward your old parts to them so they can match them up before supplying you their new parts?

I don't care now as long as the outcome is a fully working clutch.

Cheers Mike

[Bibs 11,165]

Who was the supplier Mike out of interest?

[Rich H 4]

Seems odd to use a bigger driven palte, there isn't much room for a bigger plate on mine!

A non-flat flywheel would give what you reported, only contacting the outer edge so it seems a bit harsh to reject the clutch before that ias rectified (Unless it was all done by the same place!)

Just put a straight edge across the fly that will show you if it's flat or not. Blanchard grinding is the only way to be sure of a good surfce though (The outer area where the cover plate attaches is not as critical though)

I'd alos check that the 0.5mm step has been retained.

[G_Reaper 170]

I don't really want to mention the company at the moment as they have all my clutch flywheel etc and are trying to rectify their error. They are very well known in Lotus circles.

They machined the flywheel and the step was correctly put back in. The reason I sent the flywheel back was because the flywheel was visibly not machined correctly when a flat edge was placed across the friction surface. It was approx 5 tho out.

I will let you know the outcome.

Cheers Mike

[Rich H 4]

The step is only ~20 thou so that is quite an error...!

Hope it gets sorted!

[G_Reaper 170]

Still got problems!!!

I refitted the new standard clutch along with re machined flywheel, pressure bled the system. set the pedal up stop and push rod length to achieve full travel from the master cylinder. The slave cylinder adjustment checked. I still have no clutch!!!!

If the engine is off and the car is on an incline and in gear (no hand brake on) thus stopping the car from moving you can push the clutch pedal to the floor and as the pedal get to its lowest point the car will start to move. This indicates to me the clutch is just not quite disengaging. (You cannot select gears with the engine running)

I am wondering whether the flywheel is now the cause and whether I can rectify the problem in anyway without removing the gearbox etc but by altering the hydraulics.

Any suggestions??

Cheers Mike

[sanj 12]

Bleed the clutch again, using the old-school two person method. I have yet to succeed with pressure bleeding the clutch after replacing any hydraulic components, but have always been able to make it work with a followup two-person bleed.

[G_Reaper 170]

Thanks Sanj.

You were absolutely spot on I now have a clutch!!!!!!!

Cheers Mike

[MartinL 19]

Hi Mike, great news, .............................now sort the brakes!!!!!!!!