Sienna PI Posted July 8, 2009 Share Posted July 8, 2009 Hi!Clutch pedal on my mk2 pi is biting on the floor -ie: i am finding it hard to stop the car and am having to be ready to move off straight away on lifting the pedal.The clutch came to me on a high mileage engine and i have done at least 70 000 miles on it!i know that the slave cyl is ok and that the correct alignment is connected to the gearbox crossarm. Sorry to be longwinded but my question is...Is there a way of confirming the clutch itself or could it be something like a broken spring in the master cyl?Ps the release bearing is very noisy with foot off of the clutch pedal. Link to comment Share on other sites More sharing options...
Lord Sorbington Posted July 8, 2009 Share Posted July 8, 2009 When you press the clutch pedal does the clutch actuating lever move over its full travel? If not, it would tend to suggest a fault in either the master cylinder or slave cylinder. If you suspect the master cylinder then it may be worth dismantling it and rebuilding it anyway, it'd be cheaper and easier than replacing the clutch and may be the cause of your problems.Obvious question but have you tried bleeding the system to see if that helps? Can you adjust the point at which the slave cylinder connects to the clutch arm to give more travel?Does the clutch slip? Unfortunately, even if it doesn't, it's quite possible that the clutch assembly has developed a fault which prevents it from releasing properly in which case you'll have to remove the gearbox for a look. Link to comment Share on other sites More sharing options...
mikew Posted July 8, 2009 Share Posted July 8, 2009 Assuming its not the hydraulics, its almost certainly the cross shaft pin broken (or breaking) in the fork thats on the cross shaft in the bell housing.Even new ones tend to break, and when they do, they allow too much movement in the clutch actuator. Check the hydraulics and if they are ok, be prepared to remove the gearbox (removal and replacement will take a day). if the pin is broken it should be obvious, but you may not be able to remove it all, which often leaves the actuating fork stuck on the cross shaft.this will need cutting off. So before removal buy a new clutch fork and pinat the same time it would be worth replacing clutch cover plate, clutch and release bearing.good luckmikethe forks are often modified by drilling the arm and cross shaft to take an additional roll pin, which usually prevents the problem occuring again. Link to comment Share on other sites More sharing options...
AlanChatterton Posted July 8, 2009 Share Posted July 8, 2009 My guess would be the clutch pin too!Usually, if left it will get worse as the shaft slowly rotates, then you get no clutch at all.Pull the box out! Link to comment Share on other sites More sharing options...
CRAJ Posted July 10, 2009 Share Posted July 10, 2009 Could extreme crankshaft endfloat cause this too, or would the thrust washers have to drop out before this sort of thing happened.Colin. Link to comment Share on other sites More sharing options...
mikew Posted July 10, 2009 Share Posted July 10, 2009 The thrust washers are only 2-3mm thick, if they fail you do know about it, but you can check the thrusts by leavering the crank pulley backwards and forwards, preferably with a dial indicator to measure end float. Even no thrust washers probably won't affect the clutch travel that muchmike Link to comment Share on other sites More sharing options...
Lord Sorbington Posted July 10, 2009 Share Posted July 10, 2009 The clutch on my old BMW 3 series started to give problems which made reverse and 1st gear very difficult to select. That turned out to be caused by a broken spring within the clutch assembly. Link to comment Share on other sites More sharing options...
Richard B Posted July 10, 2009 Share Posted July 10, 2009 Badly worn thrusts (and crank thrust faces) can cause clutch change problems. Checked by levering the front pulley away from the timing chain cover.If that is the cause then the crank "quite" oftern is scrap. :'(Hopefully it's something simpler. :) Link to comment Share on other sites More sharing options...
Sienna PI Posted July 12, 2009 Author Share Posted July 12, 2009 Thankyou all for your suggestions etc.I will try the easy options 1st then ( i think ), if the gearbox has to come out i will change the engine clutch and box in one go.If i do find the cause of the problem i will let you know!!! Link to comment Share on other sites More sharing options...
Sienna PI Posted July 12, 2009 Author Share Posted July 12, 2009 Hi!Just read some replies on Clutch II thread - have never been able to bleed the clutch on my PI without an eezibleed until the last time when we just pumped the clutch pedal, this is why i suspect something wrong the hydraulics (?)!!! -Sorry should have stated this earlier. Link to comment Share on other sites More sharing options...
Sienna PI Posted August 31, 2009 Author Share Posted August 31, 2009 I have changed the clutch for a complete Laycock unit, no problems found whatsoever other than a 3mm difference of thickness between old and new centre plates. Thanks to you all for your suggestions. I can't believe how different and easy the car is to drive now- nice light pedal and no noise from the release bearing!!!Cheers!!! 8) Link to comment Share on other sites More sharing options...
StagNL Posted September 7, 2009 Share Posted September 7, 2009 mikew wrote:The thrust washers are only 2-3mm thick, if they fail you do know about it, but you can check the thrusts by leavering the crank pulley backwards and forwards, preferably with a dial indicator to measure end float. Even no thrust washers probably won't affect the clutch travel that muchMy thrust bearing on the rear face was completely eaten up after dropping out - didn't notice a thing except selecting reverse was always a crunchy affair.Julian Link to comment Share on other sites More sharing options...
Sienna PI Posted September 8, 2009 Author Share Posted September 8, 2009 Nigel Gair kindly came to check the end float before i went ahead with the clutch change just in case the washers had failed , and couldn't find a problem. Fingers crossed!!! Link to comment Share on other sites More sharing options...
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