Pantah Wet Hydraulic Clutch

Discussion in 'Technical Help' started by Multiverse, May 9, 2016.

  1. Hi rebuilding a 650 allazura with a wet clutch and the hydraulic actuation. I appear to have something missing! On the end of the clutch there is a shaft/pin which has half a dozen ball bearings in it. I have this. Inside the cover there is the hydraulic piston which is hollow - I have this. Looking at the parts diagram there appears to be something between the piston and the top of the clutch.
    What is it? Does anyone have one? Could someone sell one? Could someone photograph one? Could someone measure one and let me know (I should be able to make one). When it runs (hopefully soon , it would be nice to try a few gears and have a run. One phot shows the inside of the cover with the hollow piston and the second is the parts page showing the piston and a mystery part on the end. IMG_1700.jpg
    Thanks in advance for you help.
    Keith MM
     

    Attached Files:

  2. I'd assume that it's similar to the hydraulic clutch on the 750 Paso engine. It has a bearing inside the piston and what they call a bush inside the bearing. The bush is in fact a very short push rod that presses against the clutch pressure plate when the clutch is operated.
    The Alazurra must have a similar setup or the piston would spin with the clutch when the lever was pulled.
     
  3. This excerpt from the Paso 750 FAQ on ducatipaso.org might help.

    Repairs to the clutch slave cylinder:

    viewtopic.php?t=626

    viewtopic.php?f=1&t=3947

    note: the clutch slave cylinder is 26mm in diameter and it has an o-ring/seal on the piston. (hence the o-ring groove is in the piston)
    There are different clutch covers that look identical from the outside like the one of the 750F1. Inside it`s different though as the piston has 27,95mm diameter and the groove for the o-ring is not on the piston but in the cylinder. Interchangeability is only given if you switch the complete cover! There`s also a cover with a 31mm bore but don`t buy that one unless it comes including the piston. The 31mm piston is super rare and a cover w/o it is basically useless unless you have a machine shop make a matching piston.

    According to the F1 parts catalogues there were three clutch slave pistons:
    067516450 31mm diameter and no o-ring groove as that's in the cylinder
    067016460 31mm diameter with o-ring groove
    066516450 28mm no o-ring groove (Laguna Seca/same as on 85 Alazzurra 650)

    If you have a piston with 2 bearings inside, where the upper bearing has loose bearing balls you have the one of the 906. This one can also be replaced by the new one mentioned in the link above.
    viewtopic.php?f=2&t=7124&p=56530#p56530

    If you have problems with the clutch you may also want to remove the pressure plate and grease its pin on the rear side.

    alternative clutch piston seal:

    viewtopic.php?t=676
    viewtopic.php?f=1&t=6943

    clutch slave cylinder bearing:

    SKF 608-ZZ (same as -2Z, both means: both sides metal shielded)
    commonly used also in inline skates, skateboards etc so sport equipment shops may have it, too.

    8mm inner diameter
    22mm outer diameter
    7mm width

    Clutch Button (Mushroom Pin) Dimensions

    according to the parts catalogue there were 2 mushroom pins (#037016730 & #067016730) which difference was their material. #037016730 is made of bronze.
    The other one could still be found i.e. at Stein-Dinse GmbH Online-Shop .The order number is 067016730 and it did cost €4,25 according to the 2010/2011 catalogue. (Stein-Dinse is a german shop for Duc/Guzzi parts that has a few distributers in different countries. In US it`shttp://www.mgcycle.com . In Australia it`s Stein-Dinse in Healesville, Vic., phone: 006135-9621366)

    [​IMG]


    Clutch Master Rebuild

    Clutch master cylinder failure is characterized by a relatively sudden loss of clutch stiffness. It can give little or no warning as to its impending failure.
    The procedure to rebuild the master cylinder is relatively simple, and only requires a minimum of tools. A clean space to work and some patience is most important.

    You will need Ducati part 000047226, which I obtained for approximately $25us. The dealer informed me that there is a price increase on the way which could raise it as high as $60us.

    The procedure for this rebuild is outlined below

    WARNING
    Brake fluid can damage the paint on your Paso. Have a rag under your work area at all times!

    1. Drain all fluid from the reservoir.
    2. Remove banjo bolt from back of master cylinder that leads to clutch fluid tube.
    3. Remove choke cable from choke lever.
    4. Remove 2 allen bolts that retain master cylinder/lever assembly and withdraw the unit.

    Gather up the following tools (shown from left to right) and find a clean place to work. You will also need a bottle of new brake fluid.
    19mm wrench
    medium phillips screwdriver
    medium slotted screwdriver
    very small slotted screwdriver
    strong pick (like a dentist uses)
    14mm socket

    5. Using 19mm wrench, remove the lever retaining nut from the bottom of the assembly.
    6. Push out the retaining pin and remove the lever from the assembly.
    7. Spin the choke lever off it's mount, and remove the mount from the assembly.
    8. Remove the pushrod from the dust seal in the now exposed end of the cylinder.
    9. The seal will need to be picked out as much as possible to proceed. Be careful not to damage the inside of the cylinder.
    10. After most or all of the seal has been removed, the piston and spring should drop free. Take note of which direction the spring faces in the assembly.
    11. The seal and plastic bushing and o-ring are retained within the assembly with a press-in ring. There is a small hole in the side of the bore behind this ring, and with careful use of the small screwdriver, the ring can be distorted enough to remove easily. Also take note of which direction the plastic bushing faces.
    12. Ensure that the o-ring is also out of the bore, and lay out the parts that you removed.
    13. Lay out the new parts next to the old ones and make sure that they are all there. You will need to assemble the piston with the brass washer and seal, and the piston receiver will need to be inserted into the end of the spring.
    14. Carefully flush out the bore with clean brake fluid.
    15. Install the new o-ring in the groove.
    16. Insert the spring, receiver side up.
    17. Grease the piston and CAREFULLY slide it seal first into the bore.
    18. Now comes the tricky part. The piston must be compressed, while the plastic bushing, dust boot, and press-in ring are all installed. I found that the best way to do this was to slip the dust seal over the plastic bushing, followed by sliding the press-in ring over the dust boot. Now, slip your 14mm socket onto the phillips screwdriver, then CAREFULLY slide the screwdriver into the hole in the end of the dust seal. Holding this assembly together, use the end of the screwdriver to compress the piston, whereas the retention/dustboot assembly should drop neatly into place.
    19. GENTLY tap (the wrench works nicely) on the socket to drive the retention ring home.
    20. Remove the screwdriver and socket, and put the pushrod into place.
    21. Re-install the pin and clutch lever.
    22. Pour about 1/4" of new brake fluid into the reservoir, and gently prime the cylinder.
    23. Re-install the choke mechanism.
    24. Pour yourself a pint of Guinness, and marvel at your work!
     
  4. image.png Hi thanks for the formation. A bearing inside the Piston and a button makes sense. This is the F1 parts diagram that is a bit clearer. I can get a bearing easy enough and I can made a button on the lathe. Will report back when/ if it works!
    Best regards keith mm
     
  5. I have the same problem. Clutch cover without slavespiston.Can you share your solution? Thanks
     
  6. Hi, I turned a piece up on the lathe. Diameters were easy enough to measure. To get the depth I put a blob of plasticine in there and nipped it all up. Opened up the covers and measured the depth. Apologies I not so good at keeping notes in the garage so cannot help with actual sizes.
     
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