Clutch master replaced, may not feel right

[conesare2seconds]

Hi everyone. Put a new master and slave cylinder on the Z yesterday and think I may have made a mistake.

The old master has a very thin mounting flange and used an aluminum (?) spacer to increase the distance from the flange to the firewall. The new master had a much thicker flange and my helper advised against using the spacer with the new master on the grounds it wouldn't be needed. However, the new master doesn't sit as far off the firewall without the spacer as did the old one with the spacer.

After buttoning everything up we had some trouble bleeding the system. My question is: should I have used the spacer and could omitting it be contributing to it not wanting to bleed?

The pedal seems to have much shorter travel now. The way I envision the linkage, using the spacer would raise the pedal and increase travel. My helper says using the spacer will lower the pedal and decrease travel. I'm slightly dyslexic, so I don't trust my own judgment in this respect.

The clutch pedal rests approximately even with the brake pedal right now, or maybe very slightly lower. I can go compare with my other car but it is an 88 with the 4+3 and might not be a valid reference.

I'm not too anxious about getting the system bled, but maybe I should be. The Haynes manual (for what it's worth) says the slave needs to be bled, as does the FSM. The internet (same disclaimer) says the master and slave will self bleed but may require hundreds of pumps Of the pedal. We tried self-bleed, vacuum bleed and old-school bleed on the slave, with negative results, but I plan to spend more time with it today. My thinking is reduced pedal travel could be limiting its capability to self-bleed.

I appreciate your advice and experience.

[XfireZ51]

How does it shift?

[mike100]

I would bench bleed the master so you know it was primed which would minimize the bubble in the hard line.

[conesare2seconds]

Too soon to say how it drives; it's still on jack stands for now. Btw, the rear diff jack adaptor is a fantastic invention.

[Andy]

I can't speak to the spacer question but Marc H. will tell you these systems are self bleeding. I had primed the master cyl. before installing (thinking that to be good practice), then just pumped and pumped and pumped - slowly my pedal came up and it has been fine ever since.

[S.hafsmo]

I'm quote sure the spacer should be there. The flange is just thicker because it's an aftermarket casted one (Dorman?). I used the spacer. No issues.

Is this a '90?

[conesare2seconds]

Good morning. This is a 94. Putting the spacer back in shouldn't be too hard, the battery is still out. Worst part will be discon and reconnecting the clutch pedal, but we found it could be done from outside the car if someone depressed the clutch pedal.

[Z51JEFF]

When I replaced the slave at the bell housing I could not get it to self bleed so I had to use my Mityvac at the slave and pulled the fluid down through the slave cylinder. I must have pumped the pedal at least 100 times before I gave up and grabbed the Mityvac. I need to replace the master cylinder but only have a one car garage and can't get the door open fully to get to the clip on the pedal.

[S.hafsmo]

I filled the slave through the bleeder with only the hydraulic line connected. Used a small hand pump. When it started filling the reservoir I stopped and assembled the slave. Pumped the clutch 100 times to ensure it was bled and working.

Mine is however a 90, and as the bleed nipple does not break off the aftermarket ones, as it is supposed to, it must be assembled upside-down, thus it will not self bleed.

[Dds1990]

Per Jim J. I primed the slave thru the line connection on the slave with a large hypodermic needle and he advised not to depress the rod...About 100 pumps and had good pedal.

[conesare2seconds]

Update - problems solved. Thank you all for your input. Here's what happened:

When my helper disconnected the master from the pedal assembly, he didn't notice the retaining clip that fell into the driver's footwell. He fit the new master to the pedal but without the retainer in place the rod disconnected from the pedal on the first few strokes when I started to bleed the system by actuating the clutch pedal. The short pedal travel was the pedal assembly hitting the now-disconnected rod.

Today, I pulled the master, installed the spacer and reconnected the master to the pedal, this time with the retaining clip. Once bolted back up the system bled fine and is ready to go. The original failure point was a defunct slave cylinder.

The car is staying up on jackstands a little longer because Marc is sending a coolant bypass kit and under-plenum service DVD. The under-plenum vacuum components were recently replaced but there is a vacuum leak somewhere. I'll track it down after converting to a dry plenum.

[ghlkal]

Update - problems solved. Thank you all for your input.

I'm glad you got that fixed, and thanks for following up with the solution. :thumbsup: