Question and history, a little long. I bought the above car from a small car lot a month or so ago, they had installed a new clutch/pressure plate and slave cylinder. The full release of the clutch was always a problem. I had an earlier post about changing the engine, (thanks for the helpful responses). I installed a used 2.8L from a auto recycler from across the state. When I removed the recently installed clutch/pressure plate and flywheel, I expected to find the wrong application as to parts. They are what was listed on the manufacturers web site, sorry can't find the site or numbers right now.
Before I took apart the drive line for the engine swap, I bleed the hydraulic system, installed a new master cylinder, removed the rubber cushion from the damper valve and installed a nylon plug that I machined so the damper would not deflect at all. All of these changes did not help. With full deployment of the master cylinder I get 7/16" travel of the slave cylinder.

Thinking I could shim out the slave cylinder, I reinstalled the same clutch parts along with a new flywheel. The shimming did not help, only moved the slave piston further back in the slave cylinder. I still have only 7/16" of travel and when the engine warms up, I do not get a complete clutch release. The only solutions I can think of are to either use someone else's clutch parts, (suggestions?), or to possibly reduce the bore of the slave cylinder for longer travel.

Has anyone else experienced similar problems? And what was your solution, thanks, Don

 

To update my post, the data on the clutch disk and pressure plate are PHT (found on the net, appears to be Perfection Clutch. Their part numbers disk D48703, pressure plate C47708.
From what I see in Rock Auto the bore of the master cylinder is 5/8" and the bore of the slave is 7/8", and if my math is correct (always suspect), it works out to about double the capacity (50% stoke) of the slave cylinder. That makes sense, because the master appears to move about 1" total stroke (did not take a measurement).

Wilwood has an interesting master cylinder (available in different bores), has anyone adapted a larger capacity master cylinder?

Again thanks for your input.

Don

 

i have been getting a problem. with my clutch as well. i had replaced it because it was slipping. when i pulled out the disk it was in very good shape an still had alot of life left. but i put the new kit in any way. an it still slips every now an then just the same. like the slave cylinder is not retracting all the way.

i am going to try bleeding it again. i havent got any air bubles the last few times i tryed. so if you figure any thing out please let me know. i am going to fiddle with mine again fri night so i can be ready to hit the trail again this sat.

if i find out any thing usefull i will be sure to let you know.

 

found my problem. witch might be the same as yours. my clutch master just started leaking today. i have to installed a new one. an it works like its supposed too. an i am getting full travel now of the slave cylinder.

sounds like you need a new clutch master. i re-read your thread. your master is worn. an the seals inside arent able to build up the pressure to compress the fluid to push the slave cylinder. this happens because the master will wear the internal bore out causing leak by on the hydraulic clutch cylinder. works better when its cold because the fluid is thicker dosnt leak by so easy.

 

Hello:

Thanks for your responses about the clutch, I had changed the clutch master cylinder with a new unit from Rock Auto. If this unit had less volume than the OEM, don't know, but had the same results as the original unit on the car.

What appears to have solved my problem, is that I adapted a Wilwood master cylinder with a .75" bore, this is close to twice the volume as the old master cylinder (about 5/8" bore) and I now don't have any problems with full release, and will be adjusting the travel so not to over travel the pressure plate. The unit I used is part number 260-1304 and bought it through Summit Racing, this is a small unit and fit in the same tight space as the original. Received the next day with normal delivery. Changes I had to make were, elongate the mounting holes, (the trooper has the mounting studs about 3mm further apart), remove the boot until pushing the cylinder through the firewall, then reinstalling, making a brake line with US threads on one end for the clutch master cylinder and a metric on the other end for the dampener valve. Also the actuating rod is shorter and I used a 5/16-24 coupler nut on the bracket on the brake pedal. Conversion went fairly smoothly and am satisfied with the results. There is no free lunch, since the volume displaced is about double, the required force is about doubled, but it was so easy before and could easily use my hand to apply, not objectionable now using leg pressure.

Thank again for help and observations.

Don

 

nice happy you got it worked out.