Lotus Elan

s4 clutch pedal travel

PostPost by: steve71 » Thu Mar 30, 2006 10:10 am

Hi John,

Actuation point and feel are consistant in my Sprint regardless of how many times I pump the pedal. This is with the car parked. Pretty sure it's the same whilst driving.

Steve.
'71 Sprint DHC
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PostPost by: Hamish Coutts » Thu Mar 30, 2006 12:10 pm

John,

I have, not long ago, replaced the seals on both the clutch master & slave cylinders and fitted a new aeroquip flexible hose at the slave cylinder end. I have bled the system several times with a pressure bleeder and with her indoors (who is also part owner!) doing the pedal pumping. Working on a slave cylinder with the exhaust in place is a b%$&er of a job on a +2.

On first touch on the clutch pedal the damned thing operates almost on the floor. After 2 or 3 pumps the actuation point is a lot higher. (makes for interesting take offs in traffic as clutch actuation position feels almost random). I am convinced that there is still air in the system but for the life of me I can't get it out. :cry:

I replaced the seals because the old ones were leaking and the rubber flexible hose because it had a gash in it. The clutch actiation point then, was about 2/3 of the way up off the floor and consistent. That's what I want to get back to.
I think my brake bleeding problem comes from the position the car is in when I am bleeding the clutch (it's nose up on ramps). I am going to take it to my local garage to get it on a hoist and maybe even slightly tail up and see if that makes any difference.

BTW - the clutch is properly adjusted.

Regards,

Hamish.
"One day I'll finish the restoration - honest, darling, just a few more years....."
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PostPost by: steveww » Thu Mar 30, 2006 12:39 pm

I had total clutch failure on my S4 when the master cyliner dumped all the fluid in to the footwell :(

When I replaced the master cylinder and new braided pipe I noticed that the (Hmm not sure of the correct name here) bit where the cylinder rod joins the pedal was very worn. About 1.5" of pedal travel was just the slack in the worn bits being taken up. After fitting some new parts the clutch action is a lot better.

It is easy to check this. Just go head down in the foot well with a torch (flashlight) and operate the clutch pedal by hand you will soon see any play in the system.
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PostPost by: paros » Tue Apr 04, 2006 6:40 am

Suggest you look at the push rod and the fork where the pin goes through the fork this often becomes oval. The ratio of the pedal then amlifies this .020 of clearance to half an inch.
Richard
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PostPost by: jgrover » Tue Mar 26, 2019 3:56 pm

I had this problem, then after a 10 year layup I tried the clutch and after some effort and it not moving at all it went straight to the floor so I had to re-build the master and slave cylinders.
This revealed the problem - BOTH cylinders were seized in their extreme positions so the previous problem was probably down to them not returning completely to their place of rest and so the full volume of hydraulic fluid was not being used.
Afterwards it was much better, but I reckoned I could go one better still - the original push rod from the clutch arm to the master cylinder is non-adjustable - if it were adjustable then I could increase the travel of the pedal - this might make the pedal a little higher, but a small price to pay for better clutch disengagement.
How to do it? From ebay I bought a new cylinder for a Landrover (Defender I think) which has a threaded push rod and I bought a clevis fork and pin threaded the same (5/16 UNC I think). You can't use the Landrover master cylinder because the mounting holes are too wide and it is 3/4 bore not 5/8 and this might work but it is a 40% increase in clutch effort. SO just switch the push rod. You will have to trim the push rod by trial and error, but with clevis fork it is longer than the Lotus one
I had to relieve part of the back of the clutch arm because the clevis fork I bought stopped the arm coming back as much as I wanted, but just 10 minutes with a Dremel did this.

Result - lots of travel, good clutch disengagement.

I also replaced the plastic clutch hose with a stainless braided one and made a heat shield to fit on the bell housing to shield it from the exhaust.

Total cost - about ?20 for the pushrod - and I still have the Landrover one less push rod that could be sold.
Stainless hose cost about ?28.
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