Trouble bleeding the slave cylinder on1989 vette

I have a 1989 vette with a 6 speed manual. I just replaced the clutch slave cylinder on the car and I cannot get the cylinder to bleed out. I have tried to gravity bleed the system, and that didnt work. My manual says that 1988 to 1996 the cylinder can be bled with the cylinder installed. I have tried bleeding the system with it installed and removed from the car. I do have the front end jacked up to access the cylinder. Any suggestions would be appreciated.  

i have for externally mounted gm slave cylinders...

its a pain.. but it works... and it takes 2 people..

this is a push type clutch if i am not mistaken.....  if its a pull type... its wrong but you will get the idea...


with one person with their hand ready to push the clutch pedal...

i remove the slave cylinder mounting bolts.. but not the line....    i push the rod all the way in to bottom the piston...  i normally have to push this against something...  as soon as its bottomed... and i am holding it.. i have the guy above pump the clutch pedal.... each stroke the piston pushes out...  i allow it only that much by holding tight to the body of the slave cylinder .. yes it's hard to hold do to the internal spring..   after several pumps the slave cylinder piston will be at the snap ring...   the reason to have the guy above use his hand is with his foot.. he can exert enough force to blow the snap ring right out of the end...   now.. the when the piston is extended.. the pedal will get hard and high.. won't depress like normal   as the slave cylinder is at max stoke...    if the pedal is firm...  there is no air left in the slave cylinder..

i normally have to do this 2 times...  the second time...   i have the guy above keep his hand on the clutch pedal.. while i install the slave cylinder...   letting the pedal off only enough to let the slave cylinder seat against the transmission..

pushing the piston all the way to the back will send most of the fluid up into the clutch master... but if you let the piston extend without pumping..   it can and usually will capture more air past the seal and cause you headaches in bleeding the system..


i have had other mechanics borrow my pressure bleeder ball.. and run through several gallons of my brake fluid trying to bleed some of these systems...  one went through 50 bucks worth of LMAgt brake fluid for my rover cars...  then topped it off with dot 3 contaminating the remaining fluid..   ruining the 500 buck master cylinder i had just gotten smuggled back from england...  

i should also say that i have loosened the bleeder screw slightly...

made sure the clutch master was full...  

repeatedly pushed the clutch pedal rapidly.. but only about an 3/4 inch...

why... pulsing the clutch pedal will start to build pressure in the cylinder..   if you do not move the piston far enough to cover the fill port in the master... it won't pull fluid back......     its hard to know how fast...  and how far...

i understand that some clutch masters have adjustable push rods...  so you can change the height of the pedal... and to adjust the clutch push rod to the proper stroke... so when the pedal is at its upper stop.. the clutch master piston is fully seated against the snap ring and retaining washer..

i have had problems with similar clutch master cylinders on jeeps.. where there is a significant amount of aluminum floating in the system...   this is because of the jeeps upwards push rod angle...   it is far enough upward that the steel piston as its is pushed off center.. digs a groove in the master cylinder bore... reducing the amount of fluid displaced...  making it hard to shift and to grind gears going into reverse...  

i ran across this article over at the other corvette magazine on this site..


http://www.corvettefever.com/howto/84759/index.html

it shows a slightly different way of bleeding the system


post what happened????/  

Thanks for your help. I ordered up a new master cylinder to go with the new slave cylinder as stated in the site you offered up and it was simple. I felt all along that I should be replacing the master cylinder along with the slave cylinder and this article just comfirmed that. After installing the new master and following the step by step on bleeding the system offered up on the site it was easy. Had the system bled within 10 minutes.