Clutch: Master, slave or stuck disks?

Discussion in 'Drivetrain' started by desert_max, Feb 18, 2020.

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  1. Feb 18, 2020 #1

    desert_max

    desert_max

    desert_max

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    Well, I usually like to be the guy who answers technical questions rather than asks them, but I’m secure enough in my masculinity to know when to ask I Vmax experts. The Vmax is a different beast. Here’s why.

    Among the many issues with my ‘86 when I got it was zero clutch. There was no hydraulic action at all. The spooge hole was plugged, and so I introduced new fluid and bled the system down. It now seems as though there’s a reasonable lever resistance and there appears to be some hydraulic action, but the clutch is not releasing. Given that there’s no Visible means of verifying clutch pack movement, how can I quickly determine whether or not the disks might not be frozen together as opposed to a real hydraulic problem?
     
  2. Feb 18, 2020 #2

    Itgoes

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    Itgoes

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    Easy enough to pull the clutch cover off and take a peek.....with the bike on the sidestand you won't even lose any oil.
     
  3. Feb 18, 2020 #3

    desert_max

    desert_max

    desert_max

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    Yeah, guess I should just suck it up and buy the gasket, huh?
     
  4. Feb 18, 2020 #4

    Fire-medic

    Fire-medic

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    If it runs, front brake on & dropping it into gear should free-up the clutch pack, if they're stuck-together. OEM friction discs for me. You do have oil in the window, yes?

    I'd pull the left side cover, and remove the slave cylinder, one that-old is probably filled with crystallized brake fluid, w/a crusty piston, sticking, which would explain the lack of full movement. The piston won't fully retract, nor fully-release the clutch pack. You probably can clean everything and restore its function when it's bled and back installed. I'd blow-out the lines too.

    https://www.vmaxforum.net/threads/clutch-slave-cylinder-replacement.45011/

    VMax clutch slave cyl.01.jpg
     
    Last edited: Feb 18, 2020
  5. Feb 18, 2020 #5

    desert_max

    desert_max

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    1862CD64-85F3-4C48-8890-394B21F54A2B.jpeg Thanks. Clutch work is definitely in the queue. After carbs, Vboost servo, ignition sorting and fork seals. Bike currently looks like this:
     
  6. Feb 19, 2020 #6

    Fire-medic

    Fire-medic

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    If you look in the hardware store, Home Depot, Menard's Lowe's, etc, for PVC 'knock-out' plugs, used in plumbing, you can get cheap caps which will friction-fit perfectly into the VBoost to carb rubber donuts. Much-better than a dirty shop rag! Probably less-than a bottle of Gatorade at the Home Depot checkout line refrigerator, for four of-em.
    https://www.homedepot.com/p/Oatey-1-1-2-in-Inset-Plastic-DWV-Test-Cap-with-Knock-Out-39100/100132303

    Sorry to-see someone butchered your wire harness.
    yellow-oatey-pvc-fittings-39100-64_1000.jpg
    VMax wire harness cut wires (2).jpg
     
    Last edited: Feb 19, 2020
    El Canadiense likes this.
  7. Feb 19, 2020 #7

    desert_max

    desert_max

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    Not sure what you're seeing, but this harness is virgin as the driven snow. PO didnt change or mod anything on this bike.

    Thanks for the tip on plugs. Been a rag stuffer forever.
     
  8. Feb 19, 2020 #8

    Fire-medic

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    OK, now I see that the nylon plug is poorly-defined in your pic, its shape is washed-out and blends-into the background. The female connector appeared to me to be cut-off.

    Don't forget to do the 'crimp-fix' solder-job by the battery.
     
  9. Mar 5, 2020 #9

    desert_max

    desert_max

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    CA2C84D4-8D83-44E8-9CA7-71C1C66075F2.jpeg And the answer is:

    Stuck plates. Bike was idle for a while and the friction and metal discs decided they liked each other a little too much. All fluids appear fresh. Even the oil I drained out was clear as honey. Things are coming together. Might even get it done before the mean season (Arizona summer) arrives.

    I need to learn how to manufacture time. What a precious commodity…
     
  10. Mar 6, 2020 #10

    Fire-medic

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    Usually just putting the front brake on, and putting it in-gear, will 'shock' the friction discs and 'steelies' loose. I also encountered a similar problem with aftermarket friction discs from Barnett on my 'widowmaker' Kawasaki 500 Blue Streak two-stroke triple cyl. I would always have to 'cover' the front brake lever when I started the bike in neutral, and then put it in gear, for the first time of the day. The bike would always lurch-forward, because of the sticking discs, it happened overnight. I could usually ride the remainder of the day without it happening again, but I always used the front brake when kicking it into gear, just in-case.
     
  11. Mar 6, 2020 #11

    Fire-medic

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    You didn't have any-other issue? That's good. Since this is I believe a 'new-to-you' bike, you might want to see if those are aftermarket discs, as that could be your problem. I like the OEM Yamaha discs. Have you replaced the innermost half-width friction disc, and removed the spring-steel band? The parts which act like a slipper clutch, easing downshifts.
     
  12. Mar 6, 2020 #12

    Fire-medic

    Fire-medic

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    Sorry, double-post.
     
  13. Mar 6, 2020 #13

    desert_max

    desert_max

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    I didn’t have the option to drop it into gear with motor running. Carbs are still off. Multiple parallel repairs going on. A few years ago, OK a few decades, I had a ‘71 Bonneville that the clutches stuck on every single winter. What goes around comes around I guess.

    I just wanted to provide closure for this thread and I’m also getting a little giddy finally seeing some progress. After a flurry of activity, I’m getting really close to buttoning this thing up and taking a maiden voyage.
     

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