Clutch Fork Travel Question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

dmack91 · 11-22-2019, 11:43 PM

Hello all.

Trying to figure my hydraulic clutch problem out. Can anyone confirm how much travel I should have at the clutch slave cylinder/throw out fork? I'm getting about 1/2". I have searched and I found only one reference that said 1 to 1 1/8".

Truck is an 83 K20 that was a diesel converted to gas, SM465/NP205. Lots of cobbled together pieces, including the clutch being converted to hydro using stock components.

I thought lost the clutch last week, could barely get it into gear. Clutch would only disengage at the very bottom of the pedal travel, if at all. Now thinking it may be the hydro system and checking if isn't getting enough throw.

Thanks for the help.

v30crewcab · 11-23-2019, 10:27 AM

sometimes the pushrod gets bent. also, take off slave, and push it in and out to bleed it. if the fluid got low it might have got an air bubble in it.

CANUCIT · 11-23-2019, 11:05 AM

as the clutch wears there is more travel, you might have to put in another shim

dmack91 · 11-23-2019, 01:49 PM

Nothing is bent and I just put in a new clutch. Getting ready to try to bleed the system now.

**1774btcrew** · 11-30-2019, 01:13 AM

The rod as well as the Z bar will get grooves worn in them and not engage the clutch as far.

nonstop · 11-30-2019, 11:56 PM

Hydro system would be my first guess. I lost a master once and a slave another time or two. Both times, I progressively lost my pedal until the clutch would not disengage.

**1774btcrew** · 12-01-2019, 12:22 AM

Quote:

Originally Posted by nonstop

Hydro system would be my first guess. I lost a master once and a slave another time or two. Both times, I progressively lost my pedal until the clutch would not disengage.

They weren't hydraulic until 1985. Doesn't mean it couldn't have been changed at some point

dmack91 · 12-01-2019, 01:29 AM

Thanks, IT is a hydro system. Bleeding the system got me going.

**1774btcrew** · 12-01-2019, 01:47 AM

Quote:

Originally Posted by dmack91

Thanks, IT is a hydro system. Bleeding the system got me going.

That is nice it has been upgraded to hydraulic, I like that system better

nonstop · 12-02-2019, 02:29 AM

Quote:

Originally Posted by dmack91

Thanks, IT is a hydro system. Bleeding the system got me going.

Might want to go ahead and replace both components. The system got air in it somehow (possibly from a bad seal) and will likely get more air in it again.

dmack91 · 12-02-2019, 09:55 PM

I should have replaced the slave too, I know, but was trying to get it back in service before the snow arrived. Going to pick up a mityvac tomorrow as I'm still fighting air in the system. Laying under it in 12" of snow leaves a lot to be desired.

11-22-2019, 11:43 PM	#1
dmack91 Registered User Join Date: Jan 2011 Location: Redmond, OR Posts: 760	Clutch Fork Travel Question Hello all. Trying to figure my hydraulic clutch problem out. Can anyone confirm how much travel I should have at the clutch slave cylinder/throw out fork? I'm getting about 1/2". I have searched and I found only one reference that said 1 to 1 1/8". Truck is an 83 K20 that was a diesel converted to gas, SM465/NP205. Lots of cobbled together pieces, including the clutch being converted to hydro using stock components. I thought lost the clutch last week, could barely get it into gear. Clutch would only disengage at the very bottom of the pedal travel, if at all. Now thinking it may be the hydro system and checking if isn't getting enough throw. Thanks for the help. __________________ 68 Chev C20- son has it now 83 K20 - bought from son 70 C20 - in progress

11-23-2019, 10:27 AM	#2
v30crewcab Registered User Join Date: Apr 2012 Location: Chatt Tn Posts: 977	Re: Clutch Fork Travel Question sometimes the pushrod gets bent. also, take off slave, and push it in and out to bleed it. if the fluid got low it might have got an air bubble in it. __________________ 88 military v30 crewcab shortbed 5.9 cummins, nv4500, 205 86 k30, 89 diesel burb, 76 gmc pathfinder 71 longbed 5.3 4l80 http://67-72chevytrucks.com/vboard/s...d.php?t=522535

11-23-2019, 11:05 AM	#3
CANUCIT Registered User Join Date: Nov 2017 Location: JOPLIN MO Posts: 59	Re: Clutch Fork Travel Question as the clutch wears there is more travel, you might have to put in another shim __________________ 1962 chevy short and wide 2015 z71 1967 SS Chevelle

11-23-2019, 01:49 PM	#4
dmack91 Registered User Join Date: Jan 2011 Location: Redmond, OR Posts: 760	Re: Clutch Fork Travel Question Nothing is bent and I just put in a new clutch. Getting ready to try to bleed the system now. __________________ 68 Chev C20- son has it now 83 K20 - bought from son 70 C20 - in progress

11-30-2019, 01:13 AM	#5
1774btcrew Senior Member Join Date: Jun 2009 Location: Phoenix AZ Posts: 4,594	Re: Clutch Fork Travel Question The rod as well as the Z bar will get grooves worn in them and not engage the clutch as far. __________________ AZPartsLocators on Instagram 1972 Cheyenne Super Short Bed big block "Blackie" 1977 Crew Cab GMC Short bed with 4BT Intercooled Cummins Diesel and a 4L80e "The Junkyard Dog" 1985 Crew Cab Chevy dually with 5.9 Cummins "The Big Dog" This is what my dad liked to be called by the grandkids before he passed so it seems fitting for his old truck.

11-30-2019, 11:56 PM	#6
nonstop Registered User Join Date: Dec 2014 Location: Northern California Posts: 422	Re: Clutch Fork Travel Question Hydro system would be my first guess. I lost a master once and a slave another time or two. Both times, I progressively lost my pedal until the clutch would not disengage.

12-01-2019, 01:29 AM	#8
dmack91 Registered User Join Date: Jan 2011 Location: Redmond, OR Posts: 760	Re: Clutch Fork Travel Question Thanks, IT is a hydro system. Bleeding the system got me going. __________________ 68 Chev C20- son has it now 83 K20 - bought from son 70 C20 - in progress

12-02-2019, 09:55 PM	#11
dmack91 Registered User Join Date: Jan 2011 Location: Redmond, OR Posts: 760	Re: Clutch Fork Travel Question I should have replaced the slave too, I know, but was trying to get it back in service before the snow arrived. Going to pick up a mityvac tomorrow as I'm still fighting air in the system. Laying under it in 12" of snow leaves a lot to be desired. __________________ 68 Chev C20- son has it now 83 K20 - bought from son 70 C20 - in progress



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