Spent all day today trying to bleed my clutch and was unsuccessful. Here's the story. Swapped out my transmission (zf5 to another zf5) I changed out my slave cylinder as well and I bench bled it. Put it on the fork and go to bleed it and the thing will not bleed. When I've bled it in the past I just took the master cylinder reservoir cap off and pumped for a bit and was good to go. Not the case today. My dad and I spent roughly 7 hours with no luck. We tried the bleeder valve on the slave. We tried just leaving the cap off and pumping. We tried the hand vacuum pump and even bench bled the slave cylinder. Am I missing something here? Also I notice the slave cylinder seems kind of squished on the fork and doesn't really push it out very far (obviously because it's not completely bled) but it just doesn't look normal to me. Any thought? I'm really eager to try out the new tranny but this is in my way thanks all

 

I have done this a few times as recently as last weekend. if you need to bleed the whole system then you are supposed to bleed the master cylinder first. Is it possible that air was introduced in your master? I have a short piece of clear hose that came with the last clutch MC that I bought. It has a fitting on the end that goes into the MC fluid port. You bend the hose up and put the other end in the fluid res. Have someone pump the pedal and observe the clear hose for air bubbles. Make sure the end of the hose remains submerged in the fluid. When fluid in hose pumps clear and no more bubbles are observed, remove the bleeder hose and quickly replace the clutch fluid line. Next have your helper pump the pedal up and down several times and hold down. Relieve the bleeder screw and observe fluid discharge for air or whatever. Do not have helper lift pedal till screw is closed tight. Repeat process untill you are visually satisfied that there is no air in the line. Make sure the res has fluid in it at all times. Once you have done that, get in the truck and pump the pedal up and down about 20 times. At some point the pedal should start to pop back up on its own. Get it where it pops back real good and it should be fine.
One other case that occurred to me while I was typing this was when the clutch pedal lever arm wasn't moving the MC push rod enough. Some MC push rods are adjustable so that you can lengthen or shorten the push rod. the push rod should just begin to compress slightly when you pop the eye of the push rod onto the lever arm. One truck that I had with this problem did not have the adjustable push rod so I moved the lever arm forward one tooth. That worked great as well. Good luck, you'll get it..

 

I just went through the clutch master / slave bleeding hassle, it's kind of a pissy job, and in doing so found out a bunch of things that don't work and a way that did work for me. I'm sure there are other ways that work, I tried a bunch that didn't before trying this.


What I finally ended up doing and worked for me was this:
-Take the slave off the transmission and bench bleed. Make sure it's right full and carefully set it down on the ground under the truck out of the way.
-Take some clear tubing and put it on the clutch line, while it is attached to the master in the truck, and run the tube into a container. Proceed to bleed the master and the line like a set of brakes. Pump the master, pinch the line and slowly let the pedal up, pump again, repeat until you don't get any air in the line. Obviously keep a close eye on the master cylinder reservoir.
-Once the master and the line are bled pinch off the clear tube with fluid and no air in it, I used Vice grips.
-Get the slave ready, pull the clear tubing off and join the line to the slave quickly. If you do it right no further bleeding should be required.
-Go through the wonderful process of installing the slave back on the transmission, not a fun job. Be careful when compressing the slave to put it back in place, it will probably **** out the top of the master and drip on you and if you work it too much too quickly you can introduce air and have to start all over (Don't ask how I know...)


When reinstalling the slave I used a ratchet strap to compress the throw out fork a little and reduce the amount I had to compress the slave cylinder.

 

Thanks for your replies. I will try these remedies either today or tomorrow. I will get back with results

 

What do you mean you moved the lever one tooth? Mine isn't an adjustable push rod and I think this may be part of my problem

 

so you found another ZF? Glad for you! I got mine road tested this past Saturday, was going to call you today to offer up my spare.

 

On my previous conversion build, I simply opened the allen bleeder and kept pouring brake fluid in the master reservoir. It bled out nicely. An important thing to keep in mind is that it'll bleed better with the nose up a little. If the drivetrain is dead level, or the rear end up, it may have a hard time getting all the air out.

 

stick your head under the dash on drivers side. look up at the cluth MC push rod. you will see a short lever arm that moves the push rod in and out. The lever arm is held onto the pedal assembly shaft by a nut. remove the nut and lever arm and you will see the shaft is splined. re install lever arm on the spline one tooth forward of what it was. I would be sure that the hydraulic system is bled first.

 

do i pump the pedal while pouring? Or just literally open the Allen key and dump fluid in the reservoir for a while?

 

I simply opened the screw and kept the master topped up. This method may or may not work for you, but it did work for me.

 

I just replaced the slave cylinder on a '92 like... 2 days ago.
The previous cylinder was leaking, which actually made it bleed really easily... but also bleed out quickly.

Anyway, what I found worked was:
1. pull cap off the master cylinder, fill most of the way up with fluid.
2. Open the bleeder on the slave cylinder.
3. Push the pedal down(should stay down).
4. Close the bleeder
5. Pull the pedal up.
Repeat steps 2-5 until you stop hearing air coming out. Check every so often for adding new fluid to the MC.

Near the end of it, you can close the bleeder, pull the pedal up, push it down, then crack the bleeder just a little and you'll get some pressure out. Once you stop seeing air, close the bleeder and then just pump the pedal for about 10 minutes. It'll slowly build up pressure and start working.

 

worked like a charm for me but now I have a good pedal but there just isn't enough throw. The clutch doesn't come all the way up to line up with the brake pedal. Now I am trying to get that spined thing off where the MC push rod actually hooks on to but am having a hell of a time getting it off. From what I understand you just take the nut off and it should come off? Not the case for me..

 

man is there a trick to getting the sucker off? Nut is removed but can't get the spined part off

 

I owe it to you guys again. Got her back on the road!!

this is how I bled it:
And after bleeding it my pedal needed to be adjusted and this is how I did that:
PS tranny is working good but my firewall has a crack so that will be next on the list.

 

Well done.