Clutch problem?

Discussion in '40- & 55-Series Tech' started by cbmontgo, Sep 19, 2012.

  1. cbmontgo

    cbmontgo SILVER Star

    Messages:
    2,859
    Location:
    Colorado
    The other day when I cold started my 1980, I couldn't get the rig into gear. Today, after sitting at a railroad crossing for about 5 minutes with the engine running, I couldn't get the truck into gear. I had to shut the engine off, put it in gear, and restart the engine.

    The issue is intermittent. Now, it is shifting fine.

    Clutch fluid level is good. Any ideas?
  2. Fast Eddy

    Fast Eddy SILVER Star

    Messages:
    11,616
    Location:
    Morgan Hill, CA
    Look behind the clutch pedal at the firewall and see if you have leaking fluid. Climb under and have someone work the pedal and see what you see. It may need to be adjusted, but if it's intermittent I'd guess you need new or rebuild clutch cylinders.

    When it fails, try pumping it up, like you would with brakes.
  3. 78fj40mg

    78fj40mg

    Messages:
    352
    Location:
    Granite Falls, WA
    I have the exact same issue. Installed a brand new clutch master cylinder (adjusted), and slave (adjusted), and it still does it intermittently. Any ideas?
  4. Fast Eddy

    Fast Eddy SILVER Star

    Messages:
    11,616
    Location:
    Morgan Hill, CA
    Brand new from where? I'll bet not Toyota. Did you replace the soft line at the same time?
  5. 78fj40mg

    78fj40mg

    Messages:
    352
    Location:
    Granite Falls, WA
    I bought AISIN oem parts and also the braided stainless steel soft line for the slave.
  6. RWBeringer4x4

    RWBeringer4x4 Mechanically Challenged

    Messages:
    1,606
    Location:
    North East, MD
    To everyone having the issue - were they bled properly? Intermittent issues sounds to me like an air bubble in the line.

    I recently went replaced the slave/master in my '75. I bled it, it was working great, parked it, then drove it the following weekend, and half way to my destination I started needing to bottom out the clutch pedal to get enough fork movement to shift.

    When I made it there, I bled it again, and got a whole bunch of air bubbles out the bleeder. It has worked fine ever since.
  7. 78fj40mg

    78fj40mg

    Messages:
    352
    Location:
    Granite Falls, WA
    I've bled mine at least three times to no avail.
  8. cbmontgo

    cbmontgo SILVER Star

    Messages:
    2,859
    Location:
    Colorado
    Started the FJ40 today and it lunges just a bit when I turn the key with the clutch in. Pumping it does not help at all. It is stuck in reverse now and will start to back up if I *barely* release the clutch. It is almost as if it needs to be "recalibrated" or loosened up a bit.

    Is this a sign of a worn out clutch cylinder? I also see where it has leaked over the years behind the pedal and on the the firewall, although it is not leaking a drop these days. I am guessing that the internal seals are shot like a brake master cylinder can do?
  9. DSRTRDR

    DSRTRDR I can mangle anything ... SILVER Star

    Messages:
    11,563
    Location:
    BTR, PHX, OMA
    yes, possible - happened on my little :cool: car after sitting for a few months - I guess it was complaining that I spent too much time working on the 40 :doh:
  10. RicardoJM

    RicardoJM

    Messages:
    231

    The lunging would be consistent with the pressure plate not fully releasing the clutch disc. You might just need to adjust the clutch slave cylinder rod. Then again...
    • the clips that hold the throwout bearing retainer to the fork may have failed
    • the fork/pivot ball may be jacked up
    • slave may be going out
    • master may be going out
    • pressure plate fingers may have failed
    • clutch system is working fine and issue is in transmission (least desireable)
    Have you removed the inspection cover and looked at things? Shoot me a pm if you'd like a second set of eyes on finding the issue.
  11. cbmontgo

    cbmontgo SILVER Star

    Messages:
    2,859
    Location:
    Colorado
    Went out and started the truck today, and the clutch basically does not work at all now. There is plenty of fluid in the reservior in the cylinder at the firewall.

    Where is a good place to start in troubleshooting this? I know nothing about clutches.

    Thanks Ricardo, by the way.

  12. nuclearlemon

    nuclearlemon not an addict Moderator

    Messages:
    14,506
    Location:
    meh-ico, colorado
    does it work any better if you pump the clutch first? where do you have your clutch pedal set?
  13. cbmontgo

    cbmontgo SILVER Star

    Messages:
    2,859
    Location:
    Colorado
    Pumping the clutch makes no difference; tried that too. The clutch pedal setting has not changed at all. It shifted perfectly and was tight up until a couple of weeks ago.
  14. bgray

    bgray SILVER Star

    Messages:
    297
    Location:
    Murphys, CA
    Have you crawled under the rig for an inspection while someone presses the clutch? Pull off the flywheel/clutch inspection cover and see if everything is operating as expected.

    Good luck.
  15. kurtnkegger

    kurtnkegger Running Topless and Dirty SILVER Star

    Messages:
    1,175
    Location:
    Denver, CO. Burbs
    This may be over simplifying, but, are you sure you have your slave installed with the bleeder nipple on top? If you have your slave installed upside down, you won't get the air out.
  16. jmylie

    jmylie

    Messages:
    623
    Location:
    CT
    Check the return spring on the clutch fork?
  17. nuclearlemon

    nuclearlemon not an addict Moderator

    Messages:
    14,506
    Location:
    meh-ico, colorado
    look at the rod on the slave to see if it's out too far and wedged
  18. cbmontgo

    cbmontgo SILVER Star

    Messages:
    2,859
    Location:
    Colorado
    Thanks, guys. I am going to run through these later this week or this weekend and see what works.
  19. cbmontgo

    cbmontgo SILVER Star

    Messages:
    2,859
    Location:
    Colorado
    So here is what I am dealing with. The slave cylinder is clearly leaking in this pic. Also, it looks like some sort of rubber "boot" is coming loose from the bellhousing when the clutch is depressed. So would a new slave cylinder be a good place to start?
    clutch cylinder.jpg
  20. destin

    destin

    Messages:
    3,602
    Location:
    portland or
    have some one press the clutch in ( not running ) while you look at your slave, see if it is even moving the clutch fork.

    did the slave rod push the clutch fork?

    I would start there.

    :)

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