Hydraulic Clutch Conversion, chime in here....

Discussion in 'U-shift em' started by moleary, May 3, 2015.

  1. 68Rivi_In_Cali

    68Rivi_In_Cali Well-Known Member

    I am not too that bracket will fit in our Buicks.

    I went with an American powertrain mounting bracket I got off of Summit Racing.

    I was a bit tied up at work but it worked out fine using the existing firewall plates. No firewall Flex.


    Heres the update!

    The Hydraulic throwout bearing also works great. The pedals line up where they are supposed to. I also got all teh necessary hardware from @ToddsGS . I got the boot for the console and the floor. Bolts and even the clutch neutral switch and harness.

    All of the parts worked great together. It does bring down the cost versus buying a full kit that still needs to be modified.

    I do need to swap out the shifter stick out for the orginal one since the shop mixed it up and put the spare chevelle one I had laying in the trunk.

    I am happy with the conversion. I used a Centerforce Dual friction clutch and a billet flyheel from TA Performance.

    I am currently waiting for the 8.5 rear I found to be built. I am adding 3.42 which should pair up pretty well with the M20 and the 28 inch tires I have.

  2. 68Rivi_In_Cali

    68Rivi_In_Cali Well-Known Member

    Here are some more pictures of the clutch master cylinder and lines
  3. josehf34

    josehf34 Well-Known Member

    how did you secure the throwout bearing ? I've seen some kits like Hydramax and Mcleaod on its bearings has pivot bolts to secure it from spinning but using the generic bearing you show in the previous page I'm not sure how can it be secured
  4. 68Rivi_In_Cali

    68Rivi_In_Cali Well-Known Member

    Here's a link to the bearing.

    It comes with studs to replace the bearing retainer bolts. I honestly didn't see when the shop installed it, but they said there were no issues and that it went together fine.

    I'm guessing the stud hold it in place from spinning.

    I pulled this from the instructions as well.

  5. josehf34

    josehf34 Well-Known Member

    Thank you! just purchased all the parts suggested by you to make the hydraulic conversion. Let's see how this goes, I will update the thread once I have information
  6. Marv Marksberry

    Marv Marksberry Well-Known Member

    043AC1CE-68FF-4A35-8C9D-A16A201D158B.jpeg ED7B9B80-7E79-4A73-8F81-34E138AB7F95.jpeg

    The first photo is how the hydraulic throw out bearing is installed on my Muncie M22. The second photo shows the bracket I made to mount the hydraulic clutch master cylinder.
    Everything you need to know is already posted here on the V8Buick board. Reading all the excellent advice here made installing my 4-speed an easy project.
    68Rivi_In_Cali likes this.
  7. josehf34

    josehf34 Well-Known Member

    I started the Hydraulic Clutch conversion using the parts suggested by @68Rivi_In_Cali, so far everything has gone really smooth but when installing the transmission I faced my first issue.

    When I calculate the air gap to adjust the throughout bearing using washers I've realized that my actual air gap is -0.150" negative so basically the throughout bearing height + transmission is bigger than the deep between the transmission bell housing and the clutch press. These are the numbers:

    Bellhousing to clutch press deep: 2.24"
    Throughout bearing height plus transmission: 2.39"
    Current air gap: -0.150"

    If I add 3 washers between the engine block and the transmission bell housing the air gap increases to 0.060" which I think is close to the recommended value, but I'm just not sure if adding washers between the block and bell housing can create any additional problem

    Any recommendation ?
  8. Stg'd 2Discover

    Stg'd 2Discover Lumpty, Lumpty, Lumpty

    It sounds like you've bought the wrong thowout bearing depth or added too much shim between the bearing and transmission. If you add washers between the block and bellhousing, you will decrease the amount of pilot bushing contact with the input shaft or it may be out of the pilot.
  9. josehf34

    josehf34 Well-Known Member

    Guys any recommendation for bleeding the throw out bearing ? I'm having problems trying to bleed my setup pumping the clutch pedal and opening the bleed line
  10. 68Rivi_In_Cali

    68Rivi_In_Cali Well-Known Member

    after I swapped the 350 for the 455 I have now, I ran into the same issue. The instructions also mention you might have to machine the face/ area where the bushing sits on the input shaft. I ground down some uneven tabs on the face and it helped me get within spec.
  11. 68Rivi_In_Cali

    68Rivi_In_Cali Well-Known Member

    I just let mine gravity bleed. Then to make sure it’s bled, I do pump the clutch pedal. It should bleed way easier than brakes. Make sure you re using the correct line for bleeding as well.
  12. Stg'd 2Discover

    Stg'd 2Discover Lumpty, Lumpty, Lumpty

    I've done in several ways for my six speed, but gravity bleed first, then do the pump the pedal pump until you get a clear stream from the throwout bearing bleed screw worked best. Make sure the bleed line from the throwout is located the top of the bearing, otherwise you'll end up with an air pocket. The pedal should feel consistent for the whole stroke, from the start, if it is done correctly.

    Also did you bench bleed the master at all? Some masters are angled so they can trap an air pocket, so to be safe you should have the master bled first. Mine was not this type.

    Another way is to pressure bleed by using a syringe in a rubber stopper through the reservoir. I tried this but ended gravity bleeding with pump bleeding until I saw a clear stream was easier and less messy.

    Don't reuse any fluid that has been bled out as it may contain micro bubbles.

  13. josehf34

    josehf34 Well-Known Member

    I can't believe I forgot to bleed the master cylinder...

    So bleed everything and now the clutch is working fine, the pedal travel is all consistent but is even harder than with the worn mechanical linkage.

    I don't know if maybe my clutch press is junk and that's why is so hard or if there's something wrong, maybe my fittings are too small ? I used copper tube 3/8" so not sure if maybe that could be the issue

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