I have over 2" of clutch pedal free travel in my 88 chevy 3/4 ton. I have tried bleeding the slave cylinder several differant ways but this doesnt change the free travel distance. what am i overlooking?

The slave cylinder should have a bleed port on the side of it. Fill the clutch master cylinder with fluid. Pump the pedal several times. Open up the bleeder valve and watch if fluid starts to come out. You may need to do this several times. You may need to pull up the pedal by hand several times. Once you have fluid dripping from the slave cylinder then close the bleeder and pump the pedal until you can feel some resistance. When you do then hold the pedal down and loosen the bleeder to let the air out. Make sure you keep the master cylinder full. Repeat until you have a good pedal.

Not sure why you replaced master and slave. might be disc or pressure plate problem. If not, then you still have some air in the system. I suggest using a MitiVac which uses vacuum instead of pumping the pedal. It is an easy tool to operate and only requires 1 person, you squeeze it by hand. Sometimes it can be stubborn air bubble, but you must have full pedal travel to clear the gears when you shift. Hope that helps.

Did u bleed slave cylinder? If not you must bleed just like you would bleed breaks.... you need to make sure you fill the master cylinder resvr too before attempting to bleed. If r his doesn't work post back with update.

you may just open the bleeder, and let it gravity bleed. make sure on the master cylinder that the piston is coming all the way back when the pedal is all the way back/up. there's an adjustment for that, on the rod connecting the clutch pedal to the master cylinder.

It sounds like the rubber seal on the Clutch Slave Cylinder piston has completely failed. You will need to replace the Slave Cylinder Assembly. To replace, undo the union nut that attaches the pipe from the master cylinder and then undo the bolts that attach the assembly to the engine/transmission. Remove the push rod from the old cylinder and place in the new. Reattach Cylinder Assembly and pipe, making sure push rod engages in socket of clutch operating fork. Bleeding the system is as follows.

1. Start with the Master Cylinder full of fluid. (Don't forget to check after a few bleeds that it stays above ¼ full so that you don't introduce more air into the line). It also helps if you have a length of clear plastic tubing that fits snugly over the tip of the bleed nipple, which makes it easier to see if there are any air bubbles still coming out.

2. Have an assistant pump the clutch pedal 2 or 3 times, then hold down, keeping weight on the pedal as fluid is released.

3. Loosen bleed nipple to release any air & fluid.

4. Tighten nipple. Assistant then lets clutch pedal return. It may be necessary to manually pull back pedal if it does not return by itself.

5. Wait a few seconds then repeat the sequence from #2.

Bleeding is complete when no more air bubbles are visible in the fluid released from the bleed nipple. If clutch is still spongy you may have to repeat the bleeding after a few days driving. If the Slave cylinder does not have a bleed nipple the union nut that attaches the fluid pipe can be used for bleeding. However, it is a bit harder to observe when all air is purged and of course very messy as fluid will drip everywhere.

It also pays to check that the clutch pedal free travel is within specification (about ¼ inch measured at the pedal rubber) to ensure the hydraulic system works properly. This is done by adjusting the push rod that links the pedal arm to the piston in the master cylinder. Adjust by first loosening the locknut on the rod at the end where it attaches to the pedal arm and turning the rod in either direction to obtain the correct free travel. One adjusted retighten locknut.

TO ADJUST PEDAL HEIGHT ADJUST WITH A STOPPER LIMITING THE UPWARD TRAVEL OF THE PEDAL.PEDAL FREE PLAY IS ADJUSTED AT THE MASTERCYLINDER PUSH ROD.IF PUSH ROD IS NON ADJUSTABLE FREE PLAY IS ADJUSTED BY PLACING SHIMS BETWEEN THE MASTERCYLINDER AND THE FIREWALL.ON A FEW MODELS PEDAL FREE PLAY CAN ALSO BE ADJUSTED AT THE OPERATING SLAVE CYLINDER PUSHROD.PUSHRODS ARE AVAILABLE IN THREE LENGTHS FOR THE 310.PEDAL HEIGHT ABOVE FLOOR IS 6.73 - 7.13 INCH PEDAL FREE PLAY IS 0.04 - 0.12 INCH.YOU HAVE CLUTCH FLUID LONG AS YOU SEE BRAKE FLUID IN MASTERCYLINDER.IF MASTERCYLINDER LOW YOU HAVE TO BLEED THE THE CLUTCH MASTERCYLINDER BY LOCATING BLEED SCREW ON SLAVE CYLINDER. REMOVE THE BLEED SCREW DUST CAP.ATTACH A CLEAR TUBE TO THE BLEED SCREW.PUT OTHER END OF CLEAR TUBE IN A CLEAN CONTAINER OF BRAKE FLUID.FILL THE MASTERCYLINDER WITH BRAKE FLUID.OPEN BLEED SCREW 3/4 A TURN.DEPRESS CLUTCH PEDAL QUICKLY.HOLD IT DOWN.HAVE A HELPER TIGHTEN THE BLEED SCREW.ALLOW PEDAL TO RETURN SLOWLY.BLEEDER SCREW TORQUE IS 5 - 6 FT LBS.IF YOU SEE AIR BUBBLES CLEAR BLEED TUBE.REPEAT THE BLEED PROCESS UNTIL YOU SEE NO AIR BUBBLES.DONT LET CLUTCH MASTERCYLINDER GO DRY WHILE BLEEDING.IF SO YOU GOT START BLEEDING PROCESS ALL OVER.HOPE THIS HELP.

You have to bleed the system again they can be a pain in the b@TT, also get a second person to operate the clutch and watch to see if the lever moves, if it does pull off the rubber and make sure you have the Y on the pivot ball inside the transmission. And if you don't get enough throw adjust the clutch rod on the clutch pedal by removing the pin and loosen the lock nut and make it longer by unscrewing the shaft. You want a half inch of free play at the top of the pedal the you want the clutch to catch about 3/4 of the way down. Also if you try to put it in gear does it grind the gears? Also did you put the clutch plate in backwards this is a common mistake even for a pro who gets interrupted by a phone call or a good-looking gal walking by, if ya need more suggestions let me know by posting to this comment.
Avid101

you need to bleed master & slave cyl master dont hold much fluid must bleed similar like brks when when starts coming out of bleeder close bleeder let sit couple of minutes air travel top of master pump pedal more repeat pumping pedal air residue will work it self out

If you have had the flywheel cut, have a clutch with a different release height (different finger or diaphram design & height) or a remanufactured pressure plate, or all of the above, you may run into this problem.
Small differences there translate to a large difference at the pedal. On linkage type designs, there were several options including longer/shorter throwout bearing or adjustable fork pivot ball. Hydraulic systems should compensate somewhat, but if you are beyond the travel of the slave cyl, I'm not sure there is anything you can do from the outside. I would check that there are no air leaks. If you have an external slave cylinder you may be able to make a slightly longer rod that connects the slave to the clutch fork. I really can't think of anything else to do at this point.
Hope this helps a bit.