GM Truck Club
THE PREMIER CHEVY TRUCK & SUV FORUM
Founded in 2004 ~ We're the #1 Chevy Truck & SUV Forum.
Silverado & Sierra | Tahoe & Yukon | Suburban & Yukon XL | SUV & CROSSOVER
Results 1 to 9 of 9
  1. #1

    Default Newbie Here, Need help with a hydraulic clutch.

    Hi All,

    This is my first post, so bear with me.

    I just recently purchased a 98' Chevy Silverado 2500 4x4 with and 454 and a 5 speed. It needed a tranny and transfercase. I installed a used tranny and transfer case with a new clutch kit and slave cylinder. Once I got it all back together I blead the clutch till I had a solid petal, then tried to take it for a spin. When I backed out of the garage the clutch was not completely disengaging, so I pulled it back in the garage, left it sit over night with the cap off. Came back the next morning, still the same. I rebleed the clutch for another hour, tried it again, still the same. I discovered that if you hold the clutch petal off the floor about 2"-3" it will almost completely disengage, but if you push it back down to the floor it starts to engage. I have a very solid petal and there is no leaks.

    I was wondering if any of you had any suggestions? I have read a lot of posts about clutch problems and most of them consist of air in the system or a bad slave. I have a new master cylinder ordered and plan on installing it, if that don't work I plan to reverse bleed the clutch. Am I heading in the right direction?

    Thanks
    Mark - Iowa
    2007 Chevy Silverado Crew Cab 4x4 2500HD Duramax/Allison
    1998 Chevy Silverado Ext Cab 4x4 2500 454/5-Speed
    1981 Chevy K30 4x4 454/4-Speed

  2. #2
    Legend
    murdog94's Avatar
    Join Date
    Feb 2008
    Location
    Cloquet, Minnesota, United States
    Posts
    8,198
    Blog Entries
    12

    Default

    I would start with the master cyl, since that is what it sounds like.. i had the smae issue with my 1988 which is the same clutch system.
    Mike

    Currently

    1997 Chevy S-10 Blazer 4X4 with 330K miles and counting (Hunting rig).

    2009 Saturn Aura XE (wifes car)

    2011 F-150 Crew 4X4

    "Hold it to the floor till you see God.... Then Brake!!!!"

  3. #3

    Default

    OK, so I replaced the master cylinder and rebled the system. It is still doing the same thing.

    Anybody else have any ideas?


    Thanks
    Mark - Iowa
    2007 Chevy Silverado Crew Cab 4x4 2500HD Duramax/Allison
    1998 Chevy Silverado Ext Cab 4x4 2500 454/5-Speed
    1981 Chevy K30 4x4 454/4-Speed

  4. #4
    Legend
    stephan's Avatar
    Join Date
    Sep 2010
    Location
    Far West, Oregon USA,
    Posts
    8,606
    Blog Entries
    1

    Default

    It sounds like your pressure plate is going overcenter. You say it's completely disengaged when you are 2 inches above the floor but if you continue on down to the floor it starts engaging again...Right? If yes, then the distances between your throw out bearing/slave & the amount of travel on the pressure plate are incorrect. This is either the wrong clutch or the wrong slave/t.o. bearing. As far as figuring out which it is, I can't tell you, but I would start checking the part numbers on your reciepts so maybe you can get an idea which it is.

    (This could also be the wrong flywheel due to incorrect depth of the recess, but if the flywheel is original to your engine, then disregard.)
    1988 Chevy C-3500 2wd (no pic)
    350 c.i. 5.7 L Stock Block, 4 Bolt Mains
    L-31 Vortec Heads, Edelbrock Cam & Intake,
    Holley 650, Flowtech Headers, Magnaflow exh.
    Jet Trans 700R4, B&M Ratchet, 4:10 gears,
    3" susp. lift kit "shadetree"
    No rev limiter, No speed limiter lol


  5. #5

    Default

    As far as i know it is the original flywheel. I just purchased the truck. I think someone has been into it before though. The pilot bushing was larger than the pilot shaft. So hard telling.

    When I push the petal down it does comletely disengage, but it barely does. You have to hit that spot just perfectly to get it in reverse with out grinding it. So when I hit that spot 2" off the floor, wouldn't there be a fairly good amount of disengaged clutch if its going past disengaged and then hitting something because the throw is to long?
    Mark - Iowa
    2007 Chevy Silverado Crew Cab 4x4 2500HD Duramax/Allison
    1998 Chevy Silverado Ext Cab 4x4 2500 454/5-Speed
    1981 Chevy K30 4x4 454/4-Speed

  6. #6
    Legend
    stephan's Avatar
    Join Date
    Sep 2010
    Location
    Far West, Oregon USA,
    Posts
    8,606
    Blog Entries
    1

    Default

    Well the throw is too long, but it's not because of the pedal stroke, it's either the to brng/slave or the clutch (pressure plate). If you don't want to pull it back out, you could just limit the pedal movement so it always stops at the exact place & you don't have to "modulate" it so carefully every time. That's got to be a PIA doing it like that.

    Were you able to address the pilot shaft/bushing issue. That could also cause a problem if the bushing is so large that it allows the pilot shaft to wobble, because then the clutch disc is also wobbleing.
    1988 Chevy C-3500 2wd (no pic)
    350 c.i. 5.7 L Stock Block, 4 Bolt Mains
    L-31 Vortec Heads, Edelbrock Cam & Intake,
    Holley 650, Flowtech Headers, Magnaflow exh.
    Jet Trans 700R4, B&M Ratchet, 4:10 gears,
    3" susp. lift kit "shadetree"
    No rev limiter, No speed limiter lol


  7. #7

    Default

    Yes I did fix the pilot bushing. The clutch kit came with the correct pilot bearing. I wonder if that isn't the reason the transmission went out.

    So your saying put something on the floor to stop the petal in the correct spot? I kind of like that idea, at least for the time being. I am just too busy to pull it back out.


    Thanks
    Mark - Iowa
    2007 Chevy Silverado Crew Cab 4x4 2500HD Duramax/Allison
    1998 Chevy Silverado Ext Cab 4x4 2500 454/5-Speed
    1981 Chevy K30 4x4 454/4-Speed

  8. #8
    Legend
    stephan's Avatar
    Join Date
    Sep 2010
    Location
    Far West, Oregon USA,
    Posts
    8,606
    Blog Entries
    1

    Default

    Yes, just something to limit the pedal travel so it stops at the same place every time. It's kind of caveman putting a block under it, but it's a quick fix & will work untill you can take the time to do it with the linkage later.
    Since the pilot bushing in the crank was too big for the pilot shaft on your replacement trans, I think they gave you the wrong trans & this might be part, or all of your clutch travel problem. Do you still have the old trans so you can measure the old input shaft, & also measure the distance from the trans flange (where it mates with the engine) to the slave/T.O. bearing mount? It's possible this distance might be less on your new trans & that is why the clutch is overcentering. (it's travelling the same distance, but in less space) It would only have to be off by a 1/2" or so to cause this. Didn't consider this untill you mentioned that the pilot bushing was too big for the new trans, & that should not be. Was the replacement trans out of the exact same kind of truck??
    1988 Chevy C-3500 2wd (no pic)
    350 c.i. 5.7 L Stock Block, 4 Bolt Mains
    L-31 Vortec Heads, Edelbrock Cam & Intake,
    Holley 650, Flowtech Headers, Magnaflow exh.
    Jet Trans 700R4, B&M Ratchet, 4:10 gears,
    3" susp. lift kit "shadetree"
    No rev limiter, No speed limiter lol


  9. #9

    Default

    The transmission was out of a 97 and I am not sure if it had a 454 or a 350. My truck is a 98 and has a 454. All the replacement parts I ordered were for a 98 with a 454. The pilot bushing that I took out was too big for the old transmission also. I am still a little skeptical that the clutch is going past center because of how it barely disengages. Sometimes I can barely get it in gear no matter where I place the clutch petal.
    Mark - Iowa
    2007 Chevy Silverado Crew Cab 4x4 2500HD Duramax/Allison
    1998 Chevy Silverado Ext Cab 4x4 2500 454/5-Speed
    1981 Chevy K30 4x4 454/4-Speed

Similar Threads

  1. Another (hydraulic) Clutch problem
    By m.gauthier in forum Chevy C/K Truck Forum
    Replies: 4
    Last Post: 01-24-2011, 08:26 PM
  2. Hydraulic clutch issues
    By okysmokey911 in forum Chevy C/K Truck Forum
    Replies: 18
    Last Post: 01-25-2010, 07:21 PM
  3. 2000 chevy trans Hydraulic Clutch cable help
    By jjc632 in forum GM Powertrain
    Replies: 0
    Last Post: 12-13-2009, 02:56 PM
  4. Air in hydraulic clutch system
    By Pedro in forum Chevy C/K Truck Forum
    Replies: 2
    Last Post: 12-12-2009, 01:46 PM
  5. hydraulic winch
    By 9191gmc in forum Chevy Silverado Forum (GMC Sierra)
    Replies: 1
    Last Post: 11-11-2009, 02:07 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •