I hear people complain about this all the time. It feels like everyone either refuses to try it or simply insists to me that it won't work.
The vacuum pump method has worked for me 100% of the time and I have never bench bled a slave on these cars. The only time the vacuum pump has not worked was when parts were broken.
I have found the exact opposite, the vac pump is a last ditch effort for me and helps but still doesn't seem to be a miracle cure. I will never put in a dry slave again. Weeks or months of using the vac pump and pumping the clutch, jacking it up etc., vice no bleeding at all if you fill it all first. I think there is a difference from getting lucky (which would be awesome) and installing it methodically to ensure there is no chance to get air trapped in the first place.
Out of the 4 times I've done it now, my last time was the best so far and it required no vac pump, and no clutch pumping, this is what I did.
I fully filled the slave squeezing it in and out while the end was inside the bottle of brake fluid. After it seemed full I continued to do it slowly for a few more minutes at different angles to ensure all the air was out. I bolted the slave to the trans and installed it into the 90 degree plastic elbow. I filled the elbow with fluid to the brim and slightly depressed the slave a few times to ensure there was no air in the slave line or plastic elbow and fluid was up to the brim. Jack the trans up into place and filled the master cylinder with new fluid and gravity drained the line into a bucket. Once I had new fluid coming through I put a cap on the line to keep it from leaking and put the cap back on the master cylinder. Seated the trans and got a couple bolts started then uncapped the line and installed it in the elbow, again fluid overflowed some as I had it filled to the brim and I wiped it up. Finished the trans install, driveshaft, exhaust, starter yadda yadda which took a few more hours. Took it off jacks and started it up and the clutch felt amazing and drove perfect right off the bat. This is the way I will do it from now on.
Slave cylinders are fragile, like baby panda eggs lol (some of you may get that reference) But here are some pointers from my experience working on the clutch systems in these cars. First off never install a new clutch without a new slave cylinder and never install a new slave dry (this gives you the highest chance of getting trapped air). Just don't do it, don't take the chance.
Also don't reuse old fluid in your new stuff use this time during the clutch install to do a fluid flush of the master cylinder and ensure you have new clean fluid. Don't save or use old brake fluid either btw, it doesn't have a shelf life once opened and will absorb moisture and contaminates from the air. I always get the smallest bottles for this reason and return or trash what I don't end up using. Its best to do the flush right before you go to put it all back together and minimize the time the cap is off etc.
Something as simple as slave mounting surface not clean or true or too much material removed from a resurfaced flywheel can cause engagement problems. Also stay away from stiffer pressure plates in upgraded single discs clutches they reek havoc on the save cylinder as well. It seems to be a gamble. I already know I don't have good luck lol
Torque specs, follow them. From flywheel to pressure plates, floater plate, slave cylinder mounting bolts etc check and ensure all torques are good and even. Also most install directions say locktite isn't needed but I would recommend a little blue locktite on all these bolts as they rotate with the drivetrain and have a higher chance of drifting over time.
I would at least inspect the pilot bearing if not just replace it each time its a cheap part, either way ensure its clean and add some fresh grease to it.
And finally some bad habbits that do affect everything over time, don't ride your clutch, take your foot off when done shifting and try to avoid holding the clutch in every time your coming to a stop. A clutch in shift to neutral and braking and sitting in neutral will all prolong the life of the clutch and slave. Don't use the clutch to hold your self on a slight up hill either lol.
