Clutch Slave Cyclinder - ZR-1 Net Registry Forums

ZR1FUN · 05-23-2010

My Z has been down for severl months waiting for my new garage to get in working shape. I blew the clutch slave doing a power shift. I was able to get in 2nd and limp home since I was only a couple of miles away. To move it around at home I pumped it about 50 times and was not grinding gears.

Subsequently I bought a new slave, my grandson and I installed it, bleed it and as we finished getting the bubbles out it locked up. I could not depress the clutch pedal to the floor. Thought maybe we did something wrong, pulled it put it back, same issue, replaced it with the old slave which I took apart and cleaned (full of gunk), same issue. I get about two thirds of the pedal depression and then it is not going any further.

What simiple step are we missing? Is the clutch master cyclinder blown and impacting the slave? I have a new clutch master sysclinder and was going to replace it as well but do not want to start it until I have the slave working correctly unless it is or could be the problem.

Doug
ZR1FUN

GOLDCYLON · 05-23-2010

Quote:

Originally Posted by ZR1FUN

My Z has been down for severl months waiting for my new garage to get in working shape. I blew the clutch slave doing a power shift. I was able to get in 2nd and limp home since I was only a couple of miles away. To move it around at home I pumped it about 50 times and was not grinding gears.

Subsequently I bought a new slave, my grandson and I installed it, bleed it and as we finished getting the bubbles out it locked up. I could not depress the clutch pedal to the floor. Thought maybe we did something wrong, pulled it put it back, same issue, replaced it with the old slave which I took apart and cleaned (full of gunk), same issue. I get about two thirds of the pedal depression and then it is not going any further.

What simiple step are we missing? Is the clutch master cyclinder blown and impacting the slave? I have a new clutch master sysclinder and was going to replace it as well but do not want to start it until I have the slave working correctly unless it is or could be the problem.

Doug
ZR1FUN

Not sure what is going on but a call to Bill Boudreau is in order. The slaves had a high failure rate out of the box. You May have done nothing wrong.

WWW.ZFdoc.com

Heres a link to his article on the have subject http://www.zfdoc.com/CHS_Actuator_Seal_Fault.htm

tomtom72 · 05-23-2010

This may be off the wall.....but what are the symptoms of a bent clutch pedal arm?

Other than that, the only thing left is the master.

XfireZ51 · 05-23-2010

Quote:

Originally Posted by tomtom72

This may be off the wall.....but what are the symptoms of a bent clutch pedal arm?

Other than that, the only thing left is the master.

I have 2 spare clutch pedal assemblies if needed. Another thought could be the throwout bearing arm may be bent.

lbszr · 05-23-2010

If it will depress to the floor with the bleeder on the slave open, or the line loosened, or before the air is bleed out like you mentioned, then I would think the problem is probably at the slave end.

mlotruglio · 03-17-2011

Did you ever fix the problem? I seem to behaving the same issues and it is looking like a pressure plate or clutch fork problem. What have you done?

Thanks in advance Matt

rhipsher · 03-18-2011

The symptoms of a bent clutch fork are as follows. Clutch engages only a few inches off the floor board. Next will be broken throwout bearings. One right after the other. Here's a good clutch fork next to a bent and twisted clutch fork.

Vettevern · 07-14-2013

What's the deal with bleeding the clutch slave on a 1990 ZR-1. The FSM says use an easy-out (I think) to remove existing bleed screw and replace with new one. Bleed and then break off bleed screw to provide clearance! Did they do an upgrade in later years that is a little better? I may need to replace clutch master so I may want to replace slave also.

POWERBRAKEBOB · 07-15-2013

I'm working on engineering a better clutch master/slave combo. The master is a piddly 11/16" piston. You have to bury the pedal into the carpet every time to shift. Third is always hard to push into. I'm planning on selling a conversion to a 3/4" or 13/16" master to push more volume out to the slave, giving more stroke to the slave. In regards to this issue, it seems the push rod is not seated into the fork. . I am also working on a slave rebuilding kit. Many power brake seals are very close to what is needed. I will post when it is ready.

POWERBRAKEBOB · 07-16-2013

Bleeding the slave is the simplest thing. Air bubbles only go UP. Fluid only goes DOWN. Usually just filling the master and letting it sit, the slave will bleed. You can also pump, SLOWLY, the fluid down to the slave, but Chevy put the bleeder on the BOTTOM. That will let fluid push thru, but the final air bubbles will work their way back up to the reservoir just pumping with the bleeder shut, or driving it to work out the last air bubbles.

05-23-2010	#1
ZR1FUN Join Date: Sep 2006 Location: Olympia Posts: 162	Clutch Slave Cyclinder My Z has been down for severl months waiting for my new garage to get in working shape. I blew the clutch slave doing a power shift. I was able to get in 2nd and limp home since I was only a couple of miles away. To move it around at home I pumped it about 50 times and was not grinding gears. Subsequently I bought a new slave, my grandson and I installed it, bleed it and as we finished getting the bubbles out it locked up. I could not depress the clutch pedal to the floor. Thought maybe we did something wrong, pulled it put it back, same issue, replaced it with the old slave which I took apart and cleaned (full of gunk), same issue. I get about two thirds of the pedal depression and then it is not going any further. What simiple step are we missing? Is the clutch master cyclinder blown and impacting the slave? I have a new clutch master sysclinder and was going to replace it as well but do not want to start it until I have the slave working correctly unless it is or could be the problem. Doug ZR1FUN

05-23-2010	#3
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,645	Re: Clutch Slave Cyclinder This may be off the wall.....but what are the symptoms of a bent clutch pedal arm? Other than that, the only thing left is the master. __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member

05-23-2010	#5
lbszr Join Date: Nov 2006 Location: dayton,ohio Posts: 425	Re: Clutch Slave Cyclinder If it will depress to the floor with the bleeder on the slave open, or the line loosened, or before the air is bleed out like you mentioned, then I would think the problem is probably at the slave end. __________________ [FONT=Comic Sans MS][COLOR=red]"I wanna go fast!!"[/COLOR][/FONT] [FONT=Comic Sans MS][COLOR=#ff0000]-- Ricky Bobby[/COLOR][/FONT]

03-17-2011	#6
mlotruglio Join Date: Mar 2011 Location: Harrisburg NC USA Posts: 45	Re: Clutch Slave Cyclinder Did you ever fix the problem? I seem to behaving the same issues and it is looking like a pressure plate or clutch fork problem. What have you done? Thanks in advance Matt

03-18-2011	#7
rhipsher Join Date: Aug 2008 Location: Houston 90 Red ZR-1 Posts: 2,320	Re: Clutch Slave Cyclinder The symptoms of a bent clutch fork are as follows. Clutch engages only a few inches off the floor board. Next will be broken throwout bearings. One right after the other. Here's a good clutch fork next to a bent and twisted clutch fork. Last edited by rhipsher; 03-18-2011 at 08:53 AM.

07-14-2013	#8
Vettevern Join Date: Apr 2012 Location: California Posts: 12	Re: Clutch Slave Cyclinder What's the deal with bleeding the clutch slave on a 1990 ZR-1. The FSM says use an easy-out (I think) to remove existing bleed screw and replace with new one. Bleed and then break off bleed screw to provide clearance! Did they do an upgrade in later years that is a little better? I may need to replace clutch master so I may want to replace slave also.

07-15-2013	#9
POWERBRAKEBOB Join Date: Apr 2010 Location: HUNTINGTON BEACH, CALIF. Posts: 38	Re: Clutch Slave Cyclinder I'm working on engineering a better clutch master/slave combo. The master is a piddly 11/16" piston. You have to bury the pedal into the carpet every time to shift. Third is always hard to push into. I'm planning on selling a conversion to a 3/4" or 13/16" master to push more volume out to the slave, giving more stroke to the slave. In regards to this issue, it seems the push rod is not seated into the fork. . I am also working on a slave rebuilding kit. Many power brake seals are very close to what is needed. I will post when it is ready.

07-16-2013	#10
POWERBRAKEBOB Join Date: Apr 2010 Location: HUNTINGTON BEACH, CALIF. Posts: 38	Re: Clutch Slave Cyclinder Bleeding the slave is the simplest thing. Air bubbles only go UP. Fluid only goes DOWN. Usually just filling the master and letting it sit, the slave will bleed. You can also pump, SLOWLY, the fluid down to the slave, but Chevy put the bleeder on the BOTTOM. That will let fluid push thru, but the final air bubbles will work their way back up to the reservoir just pumping with the bleeder shut, or driving it to work out the last air bubbles.