OK.... I have searched I have browsed I have looked high and low still can't figure this out. I have a 90 4runner that's been parked for a fair bit but run on occasion. I am trying to resurrect the beast but have been beating my head against a wall for days. The rundown: I parked it as it didn't suit my needs at the time. Started it and moved it through the last few years always at least running it around the block. one of the last times I moved it developed a coolant leak (turned out to be the hose running from block to heater core I think). But also the last few times I moved it I had more and more trouble getting it to shift. The very last time I moved it I could barely get disengage to shift. This time got in and couldn't get it to shift except grind reverse. It shifts fine for all but 5th and reverse when the engine is off and the pedal is not depressed. I figured ok I horse beat clutches a bit so ordered a new clutch Aisin. Figured well screw it I'm in there we will do clutch master and slave, rear main seal, throwout bearing, idle bearing?, and the flywheel. Got it all back together still won't disengage. Put the old clutch slave and master in as there were differences between old and new, also tried swapping the shoe that pins to the clutch pedal between old and new. (also tried new and old combos) It still won't disengage. Adjusted the master in both directions within comfort making sure it had threads still both old and new, and still won't disengage. Checked for cracks in the mount for the pedals, but none. I'm at a total loss. Did I miss a spacer behind the flywheel or something... The clutch fork I am pretty sure is ok. it seemed fine though I admit I didn't inspect it super well. I did try to pull it off too while I was in there and gave up trying to get it out. I really dont want to have to go to a shop, But I have no idea what else to do. Tonight I pinned down the clutch pedal hoping if there is by chance any air in the system it will burp out. Please help!!!!

 

Here is why "pinning" the clutch pedal down wont burp air out of the system, if the master cylinder piston does not return all the way back there is no way for air to get out or for more fluid to get in.
make sure that the pushrod from the pedal to the master cylinder has freeplay so the piston returns completely to the "at rest" position.

 

Yeah, this made no difference as well. However, this also doesn't help figure out why my clutch will still not disengage. Thank you for the info though!

 

If you don't have the pushrod adjusted correctly so that the master cylinder fully returns to the "at rest" position you can't properly bleed the air out of your clutch.
if you can't shift a hydraulic clutch you are not moving the throwout bearing far enough to disconnect the pressure plate from the clutch disc
that is either due to air in the lines or the mechanical action of the fork and throwout bearing (if you have a fork) or it can be due to a warped clutch disc
from your description it sounds like you had a slow leak in the clutch hydraulics somewhere that finally allowed air in the lines and now that you have replaced everything you need to properly bleed it.
that is the first step at the very least.

 

Yes the pushrod adjusted correctly makes a difference. I have been at this for 14 days trying different adjustments on the push rod and have bled the system more times than I can count. I realize I did not specifically say that I bled the system. But I have with every change of new/ old parts to that system so when I tried new master slave I bled, when I tried old I bled, along with every combo thereof. Sadly it's not a bleeding problem! I have also checked profusely for leaks during this whole process. With no fluid ever missing from the system I also have no inclination to believe it's a leak. Have also tried to find leaks by pressurizing the system also no results.

 

Finally took the thing to a mechanic $900 dollars later it was the friction plate being backward.

 

expensive lesson

 

Hope for that price he installed a complete new clutch assembly with new fly wheel.

 

I wish. Just used my brand new ones that I installed wrong. But I live in a little town middle of nowhere prices for everything are extra high!

 

Hey, thanks for posting the solution. Always nice to know what finally fixed it.

 

Dam! Just a couple years ago I could get my 5 speed trans 92 22RE rebuilt for $900 out the door around my neck of the woods. True though prices on everything have gone through the roof with no end in sight.

Hopefully, you will get at least 150,000 miles on the new Aisin clutch.