ZCar Forum banner

Status
Not open for further replies.
1 - 16 of 16 Posts

·
Registered
Joined
·
232 Posts
Discussion Starter #1
Hi. Been driving my 78 for a couple of weeks now after the heater core replacement and the fixed driveshaft....have a question on clutch pedal travel...It has a 5speed in it..stock, and of course the hydraulic clutch cylinder....the clutch does NOT slip, but it disengages almost immediately after pushing on the pedal...like half an inch or so...I can perfectly shift between gears with the clutch pedal only half way down. Is this normal? These clutches cannot be adjusted, right? Is it only a matter of losing the clutch soon? Thanks for the advice....
chris
 

·
Registered
Joined
·
232 Posts
Discussion Starter #3
what the *((*# did I do?

I went to adjust the rod under the dash...adjusted it about 1/2 inch and lost all my clutch pressure....spent 30 min trying to bleed the system...no luck. Nothing is leaking, and it is bleeding....although just dripping....?
chris
 

·
Registered
Joined
·
1,153 Posts
Taken from a post last Friday title "Clutch Slipping". Also, the FSM lists exact figures for pedal travel and adjustment.

Or you could try to adjust it slightly for best performance. Pretty easy to do. Where the pedal pushes the rod into the clutch master cylinder, there is an adjuster. Threads are on the rod. There is a locknut that must be loosened first, but once it is out of the way, it goes like this...

Screwing the rod in towards the pedal (counter clockwise) will let the clutch engage later relative to pedal movement, and unscrewing the rod from the connector at the pedal will let the clutch engage sooner relative to pedal movement. Unless the thing is way off, all you are doing is moving the moment of engagement/disengagement in or out. Adjust it too far in and you will have problems engaging any gears (clutch not fully activated), too far out and you will have slippage with the foot off the clutch.

This is something you can play with, and get right. Sounds like you are pretty close now, and just need a half turn or so on the
clutch engagement rod. Don't forget to tighten the lock nut. I usually loosen the lock nut, turn the rod by hand, and take it for a test spin. If it isn't right, I stop somewhere safe, and adjust it some more. When I'm happy, I take it home and tighten the locknut.
 

·
Registered
Joined
·
232 Posts
Discussion Starter #6
Well, all I wanted to do was make a slight adjustm

Well, all I wanted to do was make a slight adjustment on my clutch rod....losened the lock nut, moved the rod about .5 inch in (it was allll the way out), and I lost all my clutch pressure.....just by doing that....spent about 2 hours trying to bleed it....nothing...absolutely nothing. I am doing this on my own....and I read the manual on how to do it....the only thing I didn't do was use the teflon tape on the bleeder valve when doing it...NOW THERE IS ONLY ONE bleeder valve on the whole clutch system right? and that's on the slave? That's what I was using, but I did take off the master 2 times and it DID squirt when pressing the rod..anyway, can't believe that happened just from an adjustment. I ordered a master and slave from VIC BRIT...was actually cheaper than local stores....****..shouldv'e left well enough alone.
chris
 

·
Registered
Joined
·
651 Posts
Ok, here's my feelings on this. The adjustment under the dash is ONLY for pedal height. It is not supposed to be use to change the engagement. Once the pedal height is set and the system is bled, you adjust the engagement by setting the rod on the slave cylinder for 2mm play.
SoM
 

·
Registered
Joined
·
1,153 Posts
Well, you are entitled to your feelings about it. I know that after I recently replaced my clutch master, the pedal engagement changed. In my case, this was the affected adjustment that allowed my clutch to engage properly again.

If this has been adjusted improperly, you will not get enough pedal movement to fully release the clutch. From a system point of view, both should be adjusted when any components are changed.
 

·
Registered
Joined
·
651 Posts
Ok, I'm probably going to shoot myself in the foot here but...

The 280 adjustments may be different from a 240 but on the 240 the FSM says to set the pedal height to 8" (same height as the break pedal). All other adjustments are made at the slave cylinder. Yesterday I changed my master cylinder and guess what? With the pedal at 8", I don't get full disengagement of the clutch. This indicates that there's too much play in the pushrod at the slave cylinder but I haven't checked it yet. If I find that the slave is adjusted properly, I'll have to raise the pedal, but what does that really mean? It means the master is not forcing enough fluid into the line, in which case I would say that the master cylinder is different from the original (it certainly does look different).

In any car I've ever driven (quite a few) if the break and clutch pedals are not at the same height, something is probably wrong with the setup. (IMHO or course)
SoM
 

·
Registered
Joined
·
651 Posts
results...

I checked the slave cylinder and found that it was way out of adjustment. After adjusting it for 2mm play (with the slave pushed all the way in), the clutch was much more consistent but still engages too low, about 1/2 inch from the bottom. So I did end up raising the pedal height about 1/4 inch. Now engagement starts about 1 1/2 inch up from the floor. Now, (and Zuber you can flame me all you want but it won't change the facts) what this tells me is that the replacement master cylinder has the wrong flow rate. Changing the pedal height is an acceptable workaround if you don't change the height too much, but the real problem is that the replacement equipment is not functioning like the original. If I can find a seal replacement kit for the original master cylinder, I'll rebuild it and have my pedal back where it belongs. Oh, and Vega, when you said 1/2 inch, did you mean at the pedal or 1/2 inch adjustment on the rod? (must be the pedal, right?)
SoM
 

·
Registered
Joined
·
9 Posts
Re: results...how to adjust?

How do you adjust the slave cylinder? I've got a similar problem. Clutch disengages almost as soon as you depress the pedal. Clutch is slipping a bit. I've been through the Haynes manuals & everything else I can find, but can't find any adjustments mentioned outside of the pedal. I raised it, but that's not the problem. The slave/master are "original" - to me at least... had the car for a year. The transmission was grinding in 2nd gear & I just changed out the transmission & put a new clutch in it. But it was engaging high before & it still is. Any suggestions?
 

·
Registered
Joined
·
651 Posts
Re: results...how to adjust?

The slave cylinder has a rod coming out that pushes on the lever that goes into the clutch assembly. There's a rounded nut that pushes the lever and a lock nut. Loosen the lock nut (you'll need to push back the rubber boot). Push the end of the rod to make sure the pisten is pushed all the way into the cylinder. Now adjust the rounded nut in or out to achieve a small amount of play (2mm) in the rod, then lock it in place with the lock nut. BTW, this is from the 240Z FSM, but I think it's the same on the 260 and 280. If the clutch engages too high or slips, the rod is adjusted too long (no play) and you need to move the nuts toward the cylinder. If it engages too low, there's too much play and sometimes you need to take up all the play and a little bit more.
SoM
 

·
Registered
Joined
·
1,153 Posts
No flaming needed. You demonstrated my point. By changing only the master, which might or might not be up to OEM standards, an adjustment to the pedal height was required to get the proper clutch engagment.

The adjustment to the slave, while needed, and proper, does not allow for fine tuning like the pedal. You adjust for zero tension (2mm play). Period. If it's not adjusted, of course, adjust it. But to cure problems of proper range of adjustment, the pedal is king.

I got my replacement from Courtesy Nissan, still in it's factory box and plastic. I don't get the feeling that it pumps less fluid. There was something different about it, though. Like the position of the piston in the cylinder. Who knows. Where did you get yours?
 

·
Registered
Joined
·
15 Posts
Re: Well, all I wanted to do was make a slight adjustm

I have the same problems with my clutch after replacing the slave cylinder, andinstalling the rubber bumpers that engage cruise switch. Did you find a solution?
Thanks
 

·
Registered
Joined
·
15 Posts
I have the same problems after replacing the slave cylinder and installing the rubber bumper to the pedal (that engages the cruise switch)..Did you find a solution?
 
1 - 16 of 16 Posts
Status
Not open for further replies.
Top