I have recently put my engine and gearbox back into my plus 2 after replacing oil seals, water pump and release bearing. I have bled the clutch cylinders/pipes but the clutch pedal is soft when compressed. I can see the operating cylinder piston/release arm moving. When the engine and gearbox were out of the car I checked the clutch and pressure plates and reinstalled them. I have not had a chance to restart the engine since refitting, as I am waiting for a new ignition coil.
Any ideas why the clutch pedal is soft?
Regards
Scot
1968 Elan+2 four speed
How much free play is in the adjustment rod? It should be no more than than 1/8".
Before you get further frustrated, check how the slave cylinder is held in it’s mount on the bell housing. Will the slave move back and forth in the mount by hand? The circlip may allow a lot of motion before the slave piston moves the actuation rod. I added a second circlip on mine to lock it in place and reduce the lost motion. These cars and parts are old and eventually get worn and sloppy.
Getting all of the air out of the clutch slave is a challenge. The bleed fitting must be vertical position. Pressure bleeding works best in my case, ymmv.
Sometimes I have had fits getting the slave bled, including removing the slave, clamping the end of the piston in place and holding it above the master to get the last few bubbles out.
On edit, if you can pump the pedal a few times and disengage the clutch, it’s likely an air bubble. If not, it’s likely something else.
Scot
Does pumping up the pedal create a firmer feel, try this a couple of times leaving the pedal to rest for a few minutes in between each test.If so then it signifies air in the syatem. If it does not get firmer then You may have a suspect issue inside the bellhousing parts of the clutch.
Tony
thanks for your comments. I have ordered a couple of circlips to restrict the movement of the secondary cylinder. There quite a bit of play here.
Compressing the clutch pedal provide 10mm of push rod travel. I dont know what is normal.
I had a little slack in the copper pipe to the secondary cylinder and managed to rotate it a little to increase the height of the bleed nipple. I jacked up the side of the car as well.
I rebled the system but didnt really notice any bubbles coming out. The pedal firms up with short repeated pumps. So maybe still air in the system.
You can feel the release bearing pressing the pressure plate towards the end of the clutch pedal travel.
When the new coil arrives and the car starts i will see what the clutch is like running.
There’s always the old trick of wedging the pedal down with a length of wood to the seat base, and leaving it overnight. It can sometimes help expel that last bit of air.
Sounds like it may be air from your description of the pump up. Try Mike’s idea which as he says has helped some members, otherwise try power bleeding which is the best way to be sure the air is pushed out.
Good catch on finding that pumping up helps with disengagement. Smo’s advice with wedging the pedal down is spot on for getting the last bit of air from the slave.
What is the existing free play of the pushrod between the slave and the clutch arm? The book calls for 1/8" or 3MM. Any more than that makes clutch disengagement difficult under the best of conditions. The adjuster nut and locknut allow for the correct free play. Each part of the clutch assembly from the pressure plate to the pedal fulcrum wears to some extent, and all of that sloppy wear means reduced clutch travel.
My Workshop Manual gives the clearance as 0.08" or 2.03mm
I made a setting tool which makes adjusting the clearance somewhat easier than using feeler gauges while trying to hold the pushrod and turn the adjuster nut at the same time. 14 gauge steel sheet is exactly the right thickness (2.03mm)
Hello every one, quick update for you. The soft clutch saga continues.
The clutch firms up after a number of pumps. So i am assuming there is still air in the system
I added an extra circlip which restricted the movement of the slave cylinder.
I tried the push the pedal down and wedge it in position overnight. This did not work. I assume the air is in the slave rather than the flexi pipe that comes out of the master cylinder in a loop.
I bought a vacuum bleeder but the bleed nipple has some thread play when unscrewed which lets air in when the negative pressure of the vacuum is applied. I pumped the pedal to pressure the line before using the vacuum bleeder but this did not help.
I have ordered a replacement bleed nipple, so i will let you know if this improves things.
Good morning everyone. Quick update. I bought a new slave cylinder which has allowed me to bleed the air from the pipework.
I still have an issue where once the engine is running, I cannot engage any gears using the clutch. With the engine off i can push the gear stick into each gear and the car is in gear (i.e engine turns when pushed) . I will check the forum and then post another topic if the solution is not already posted. Regards Scot
Hi Scott, just in case you haven’t already checked it’s worth measuring the master cylinder pushrod length as new master cylinders aren’t supplied with correct one and often leads to this problem.
This has been covered on the forum before, but I couldn’t find the post to include in my messsage.
I recall having a similar problem and found that if The clutch was pushed hard to the floor, no gears could be engaged, however pushing the pedal about 3/4 of the way allowed all gears to function as normal. Perhaps you might try this and let us know. But try as I might I cannot recall how it got resolved now, getting much brain fog these days
Tony, that’s a very important point. What may be happening is the clutch pressure plate fingers are being overextended and contacting the clutch disc. My friends Super Seven had the identical issue. Adjusting the slave pushrod to allow a little extra free play solved the issue for him.
Your solution reminded me that that was the way I resolved the issue, so thanks for saving me the frustration of trying to recall the answer. This did work for me but why it occured in the first place is now buzzing round my head, another sleepless night !
Hello, thanks for your comment. While the pedal pumping firmed up the pedal (indicating air in the pipe work) the clutch has not worked since I reinstalled engine and gearbox. .
