I have a brand new McLeod street twin on the car, installed their new master cylinder, adjusted the master cylinder rod out to give it more travel, held the slave cylinder vertical while pumping the pushrod, hooked up a mitivac at 25 to get air out, and I have seen ZERO improvement.

The car is hard to get into most gears and impossible to get into reverse while running. If I extend the master cyl rod any further (than appr 1" back from the brake pedal), the entire pedal/car shakes like hell, so I backed it up to just before that point. The transmission was working perfectly and shifting smooth in all gears just prior to this installation, and it has plenty of fluid in it.

Ive exhuasted my ideas and anything Ive read on here through searches, any other suggestions?

 

With the mityvac hooked up and the line vertical and in clear sight, I was pressing the clutch pedal. The first 1" of clutch pedal travel is very light, and I can see the fluid move up the tube by that same 1" or so. Once the clutch pedal is depressed ~1" it gets to its usual resistance, and the fluid level no longer moves up for the remainder of the pedal being depressed. Is this air in my line, or the amount of travel before it becomes taught on the clutch fork, or something else?

Thanks

 

The clutch disk is not completely disengaging, this will ensure that it is hard to put in gear especially reverse. The LT1 hydraulics are self bleeding by pumping the crap out of them. I have heard that you need a special master cylinder with the Mcleod ST that provides the fork with more throw to make 100% disengagement. I also once saw a site that had you shave .030" of the bottom of the T-nut that captures the fork to do the same thing.
Again if it wont go in gear, it can only be one thing, the disk is not completely disengaged. Even if there is barely any contact with the clutch pedal depressed it will torque the tranny and not allow easy engagement.
There must be no physical contact between the disk and the pressure plate with the clutch depressed.

 

The mcleod came with the adjustible master cyl, I used it and adjusted it for more travel.

I'm down to only two possible guesses, either the slave is toast, or the pilot bearing is snagged on the input shaft. Hopefully I find a new slave cylinder to try before I have to take the tranny down and find out about about the pilot. Either way, I have to imagine it is not a 'air in the line' problem anymore, I dont think anyone has ever pumped this system as hard or as long as I did yesterday

 

Did you check the clearances between the discs, floater and flywheel?

 

I was going to, but from the directions I couldnt tell where they meant for me to check the clearance, so I just kept their spacers in the correct locations and torqued everything to spec.

I just tried replacing my slave cylinder, since it could use replacement anyway, no change in the situation (as expected)

 

So what am I checking the clearances of? From what part to what part of the assemly?

While I'm at it, I dont get how extending the adj. master cylinder out 'too far' to give me more pedal travel makes the whole thing shake when I try to start the car. It does so with the clutch depressed or resting, not that I leave it on for very long when I feel that. If I back it up a turn or 2 from there, it stops doing it. Giving it that additional pedal travel should be giving me more push on the clutch fork, rather than making it feel like it isnt disengaging at all?!? Any ideas?

Thanks

-Bad Azz Z28

 

The directions tell you to adjust the master cylinder until the clutch pedal is an inch below the brake pedal; if you did that I would think that would be shortening the travel, not lengthening the travel.

Are you sure the clutch fork is positioned correctly?

 

Did you check the gap between the bottem disk and the floater plate with a feeler gauge like it said in the directions? you should have between .020 and.025 clearance between the two. Any less the bottem disk will drag making the car hard even impossible to go into gear with the motor running. Did you make sure you used all of the shims and kept them in the same order for the floater plate??

 

The clutch pedal was originally too low and was not getting much travel. I adjusted it to what I would say is an inch behind the brake pedal, which gave it more travel. So I did that part as it says to do.

What Im saying is that "around 1 inch" is subjective, and if I turn it up just a bit higher, the whole assembly shakes like hell in any position when the car is started, as if the clutch was half engaging all the time, clutch in or out. I dont get that.



I made sure to keep all of their shims in the proper locations, everything lined up perfectly and torqued to specs.

As for the clearance between the center plate and the lower disk, how could there possibly be a clearance between the two? That center plate holds that disk there, if they dont touch, then the clutch disk would fall out immediately since nothing would hold it there up against the flywheel. Id imagine this certainly could be my problem, as it says on there an improper clearance will prevent it from releasing, but I dont see how it would have any clearance there at all. Even with that center plates' bolts loosely hanging from the flywheel, that already elimanated any clearance, and thats before I even torqued it down ??

 

If I rember correctly you check the gap right after you bolt the floater plate on but before the pressure plate is put on. Because if the pressure plate was bolted on then all of its pressure would be on the two disks and there would be no gap at all. You should have been able to move the bottem disk around with only the floater plate on there.

also is the clutch brand new or is it used?? If it is used and the flywheel was machined then you would probably have to change the spacers due to the flywheel being a different thickness

 

This was all brand new out of the box.

I talked to Gene at McLeod today, and while he thinks the clearance is off and the disk isnt releasing, he has "never heard anyone have that problem with the master cylinder being adjusted out all the way". So apparently I am a trendsetter at breaking things. Either way he is being very helpful in identifying the problem, so I'm going to take the tranny and clutch off tomorrow, and he is going to call me to walk me through this particular unit. We need to determine if is just incorrectly spaced, or if there is another problem. Hopefully its nothing I cant correct with their help.

He also verbally explained the clearancing issue with me, and it makes much more sense than how the directions stated it. Yes I knew they wanted me to check between the bottom disc and the floater plate, but seeing as mine was SO TIGHT, I thought the directions were wrong/imcomplete. Thus we think it was spaced wrong, but what should normally happen is the bottom disc will touch the flywheel and floater, but be so loose that it would fall down without the clutch tool in, atleast until the pressure plate is applied, which then has enough force to keep it in place.

 

Hey just wondering if you had any luck with your problem? Was it in fact the spacing that was the issue?