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Slow clutch pedal return

Discussion in 'Bay Tech Clinic' started by Stormin12345, Aug 13, 2021.

  1. Stormin12345

    Stormin12345 Member

    Messages:
    75
    Location:
    Sydney
    Hi folks
    Put my engine back in yesterday after it’s rebuild (still to try and start it, getting it back in the bus as my first ever attempt took all my time - guess it will be easier when I get to do it again! Any tips for how to make the oil filler tube not be such a pain appreciated!).
    As part of my rebuild have put in a new clutch including new release bearing. Have hooked clutch cable back up and the pedal is very soft and returns slowly. The cable seems fine and moving freely (that said I have no point of reference) - from the back of the bus I can pull the pedal off the floor by just pulling the cable. When the cable is disconnected from the gearbox, the clutch arm on the gearbox springs back properly when released and requires reasonable pressure to move the arm. I think I have the free play adjusted correctly. Any suggestions on what to look at that might be causing this? BTW it’s my understanding there is no return spring on the clutch pedal itself, thus normal that the pedal drops to the floor when cable disconnected, if I am wrong that could be my problem!
    My fear is that it’s the spring on the clutch release arm on the gearbox has worn/simply isn’t strong enough - doesn’t look hard to replace if the engine was out again, however having taken 3 months to get to the point of putting it in not something I want to do right now!
    Many thanks in advance!
     
  2. Barry

    Barry Well-Known Member

    Messages:
    6,192
    Location:
    Abbotsford NSW
    Are you saying there is no/little resistance when you put your foot on the clutch?

    Clutch
    • Pedal travels to floor - no pressure or very little resistance.

    1. Broken clutch cable.
      Broken release bearing or fork.
      Collapsed diaphragm spring in clutch pressure plate.
    http://www.vw-resource.com/troubleshooting.html#clutch

    Sort of thinking there is something wrong in how the release bearing, fork or diaphragm spring are working together
     
    Last edited: Aug 15, 2021
  3. Stormin12345

    Stormin12345 Member

    Messages:
    75
    Location:
    Sydney
    It certainly is very light to push down - like a modern Japanese car not what I expect from a Kombi! Your suggestions sound possible - the clutch mechanism is all brand new however. Guess I could have put it together wrong? Not sure what I can screw up - most things can only go one way around?
     
  4. oldman

    oldman Super Moderator Staff Member

    Messages:
    11,003
    Location:
    Avalon Beach NSW
    Just for background, what manual are you using for guidance when working on your bus ?
    Cheers,
    Mark
     
  5. Stormin12345

    Stormin12345 Member

    Messages:
    75
    Location:
    Sydney
    A few! I find that depending on what info I want one may be more useful than another (or sometimes contradictory or wrong as it doesn’t cover all model years or favours different markets) - I have Bentley and Haynes, plus have used Tom Wilson’s book when doing the engine rebuild. I wouldn’t be without them (or be without this forum!) or equally want to rely on just one.
    Given your question do you have any steer on which way I should be leaning?
     
    oldman likes this.
  6. oldman

    oldman Super Moderator Staff Member

    Messages:
    11,003
    Location:
    Avalon Beach NSW
    No particular question in mind……however,
    I’m assuming you have the correct bend in the Bowden tube, that the clutch cable runs through, just before the bell housing ?
    Cheers,
    Mark
     
  7. Wayne murray

    Wayne murray Well-Known Member

    Messages:
    4,746
    Location:
    Seven hills
    How much free play do you have when compressing the clutch pedal?
     
  8. rstucke

    rstucke Well-Known Member

    Messages:
    1,951
    Location:
    Wamberal NSW AUS
    have you had the flywheel machined?
    some machine shops don't realise that they must machine the outer rim of the flywheel (were the pressure plate bolts to) the same amount as the clutch plate area.
    If not done it will give you the symptoms your describing.
     
  9. rstucke

    rstucke Well-Known Member

    Messages:
    1,951
    Location:
    Wamberal NSW AUS
    Another possibility is when that outer rim is over machined which causes the diaphragm to over centre reducing the clamping pressure on the clutch plate

    Also if you didn't tighten the pressure plate up evenly you stand to crack the diaphragm spring causing the symptoms you describe

    One other.
    as the clutch plate wears the diaphragm spring increases clamping pressure on the clutch plate until there's nothing left
    when you replace the clutch and pressure plate the clutch pedal feels much lighter compared to a well worn plate
     
  10. Stormin12345

    Stormin12345 Member

    Messages:
    75
    Location:
    Sydney
    Thanks all for your responses, I have had some time away from Kombi due to work and came back to it yesterday. I went back to basics, undid the clutch cable adjustment completely and started again. I also now have the benefit of a running motor so can see when clutch actually engages/disenages. What I have found is that I have to wind the clutch adjustment wing nut in far further than I was expecting, almost to the end of the thread. When I do this the clutch is disengaged with the pedal all the way to the floor, I can engage first/reverse, and starts to ‘bite’ an inch or so off the floor. With this adjustment there is a more solid feeling to the pedal and it returns as I would expect. What I didn’t expect is that when the pedal is released there is still some tension on the clutch release arm on the gearbox eg it is not in its rest position. My perhaps incorrect understanding of free play is that there is no tension on the clutch arm at all when the pedal is in the rest position? I have attached some pictures of setup.
    @rstuke yes the flywheel was machined - a good question - I will ask the machine shop - I only have a picture of the flywheel when I put it back on the motor, attached.
    CBFEF4EE-A76C-4AF3-8485-28D8E8684BB9.jpeg CBFEF4EE-A76C-4AF3-8485-28D8E8684BB9.jpeg 3FCB6C68-0838-4035-854F-5692923B2984.jpeg 62007F82-391C-45D8-BDC1-8E21FDEE1494.jpeg 3FCB6C68-0838-4035-854F-5692923B2984.jpeg CBFEF4EE-A76C-4AF3-8485-28D8E8684BB9.jpeg
     
  11. oldman

    oldman Super Moderator Staff Member

    Messages:
    11,003
    Location:
    Avalon Beach NSW
    Have you checked that the clutch cable is correct for your bus ?
    There are different lengths available....just a thought.
    Cheers,
    Mark
     
    Wiz likes this.
  12. Wayne murray

    Wayne murray Well-Known Member

    Messages:
    4,746
    Location:
    Seven hills
    The Bowden tube to me doesn't look like their is a big enough arc or bow in the tube. Should have about 25 -45 mm in it.
    Also as oldman mention is the cable the correct length as you have the nut at the end of the travel and would have no to little adjustment as the clutch wears.
    Your clutch release arm to me should rest back into it's original position.
     
  13. rstucke

    rstucke Well-Known Member

    Messages:
    1,951
    Location:
    Wamberal NSW AUS
    As the clutch plate wears the pressure plate fingers come out more so must back the wing nut off to maintain correct free play
    I'm thinking a little driving will settle the plate in and allow you to back the wingnut off .
     
    KahunaKombi and Elsie 76 like this.
  14. splitbus

    splitbus Well-Known Member

    Messages:
    3,362
    Location:
    Brisbane
    Have you got the right release bearing
     
    grumble likes this.
  15. Stormin12345

    Stormin12345 Member

    Messages:
    75
    Location:
    Sydney
    Thanks all for your help. I certainly was wondering re clutch cable length and Bowden tube bend, neither seem right I agree, I will try and work out what I have and seeing if I can get the right ones. I don’t understand how either would change the distance of travel on the release arm to clutch pedal however? Clearly important to get right for later adjustment and to absorb movement. I will try and drive it a bit to rstukes point once I can get a blue slip and see what happens. To the release bearing I was wondering the same, however it was in the sealed 215mm clutch kit I bought - my understanding is that the only variables are clutch size? Thanks again everyone for your help
     
  16. Alpal

    Alpal Moderator Staff Member

    Messages:
    9,036
    Location:
    Melbourne Bend of Islands
    A couple of fat washers between the bowden cable and the bracket will give you a bit more adjustment.
     
    Mordred and tintop like this.
  17. T1 Terry

    T1 Terry Well-Known Member

    Messages:
    1,771
    Location:
    Mannum South Australia
    The most common cause of a lot of pedal travel required to get the plate free from the flywheel and pressure plate and an over adjustment required resulting in no free play when the clutch is released ..... is a buckled clutch plate. This happens when the gearbox input shaft is engaged in the clutch plate but not all the way in till it engages in the spigot bearing .... and the motor gets twisted away from parallel with the bellhousing ...... Very easy to do the first time you reinstall a motor or gearbox in any vehicle, a Kombi is no exception .... letting the engine hang on the gearbox input shaft will cause this sort of damage. The only real way to tell is to remove the motor, clutch pressure plate and clutch plate and sit the clutch plate on the pressure plate ..... if it is buckled you will see it as a portion of the plate does not sit flat on the pressure plate ......

    Before you rip it all out, try driving it up and down the driveway and slip the clutch a bit to remove any "furry" bits and see if that improves the clutch take up position .... you are looking for the pedal take up point to increase till the pedal is much further up. If you can achieve this, back the adjustment off a bit and retry until you get to the point reverse can be engaged with the pedal nearly on the floor .... you should be able to feel the free play at the first movement of the pedal if all is ok. If you achieve this, re-adjust the cable until the pedal free play is comfortable for you.

    T1 Terry
     
  18. Barry

    Barry Well-Known Member

    Messages:
    6,192
    Location:
    Abbotsford NSW
    KahunaKombi, tintop and oldman like this.
  19. rstucke

    rstucke Well-Known Member

    Messages:
    1,951
    Location:
    Wamberal NSW AUS

    My opinion
    Won't change the way the clutch works
    Will have a problem with wear where the boudon and steel tube meet. This is why the radius sweep through the boudon
     
    Barry likes this.
  20. Barry

    Barry Well-Known Member

    Messages:
    6,192
    Location:
    Abbotsford NSW
    Fair enough

    Reckon you have changed a few more than the 10 or so that I have done :D
     

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