Well, I decided it must be a slave cylinder issue. I'm going to go back with OEM, and hope it lasts the remainder of the clutch life. When I get a new clutch, I'll install one of the zspeed slaves. Supposedly the new slave will show up tomorrow. I pulled the transmission this evening in a little over two hours of wrenching. I also disassembled the master cylinder and it had a bit of black stuff in it, but other than that it looked perfect, so it's going back in. How it sits now:



I also picked up a transmission stop off tool from harbor freight:

http://www.harborfreight.com/transmi...ool-98060.html

It's well worth the $7 and fits right in the back of the transmission to keep fluid from spilling everywhere when you pull the drive shaft.

If anyone's interested, I'll post back here and let you know if the new slave cylinder fixed my problems.

 

Patrick,
Sorry I missed your post over the weekend and just saw about tearing down for a CSC swap today. I think given the simplicity of the master cyclinder internals and the propensity for even the newer CSC's to randomly go bad I'd say you've made the right call. Even though the master is easy to swap I highly doubt it was causing the random issue you've been seeing.

When it all goes back together make sure the clutch rod angle is set to angle down slightly towards the driver by adjusting the brackets down. If the rod is set on an up angle to the master cylinder you'll get into that bind you were feeling around mid stroke.

Keep me posted.
Ryan

 

So, any confirmation about the compatibility with the ZSpeed Master Cylinder ?
http://www.zspeedperformance.com/ZSp...ZSpHDCombo.htm
Thanks for advise !

 

Greg, the Z Speed Master Cylinder has not been confirmed, however I strongly suspect they provide you with a new clevis fork due to one of two reasosns. Either the clutch rod and fork are a different length from Nissan OEM ones or the clutch rod and fork use a different thread pitch/size.

However if there's enough interest and people switching to use the Z Speed Master then I can certainly make a compatible version of the AFP Slider assembly to work with it pretty easily and make it an option during ordering or as a stand alone upgrade component for those who already own an RJM Pedal.

The RJM Pedals are already fully compatable with the Z Speed HD CSC (Concentric Slave) as is with no changes.

 

Our Clevis has a 5/16" 24 thread to fit the Wilwood master rod, We make them exactly like the stock clevis with the exception of the thread size/pitch. It will come out in the same spot as the stock master.

I believe from what I have read, you make a new clevis for the stock master to work with your pedal bracket? If so it would require a special clevis to be made to adapt our MC upgrade to your pedal.

 

CuztompartZ Thank You for chiming in. I was planning to email you today about your Wilwood Masters.

Yes, the RJM Clutch Bracket sets have a custom designed fork riding on twin bearings where it attaches to the Fulcrum Point Adjuster mechanism (AFP Slider)

So to make the RJM Pedal system compatable the only change required would be to tap the RJM fork 5/16-24 as opposed to the factory metric M8x1.25 during fabrication.

For anyone interested in getting a ZSpeed Master Cylinder compatable AFP Slider assembly I can have them available within the week.

 

I finally got it bled out on Wednesday evening. Last night I readjusted the pedal, adjusted the shifter plate, and put the interior parts back together. I took it out for a test drive and everything feels good now. I think the slave was the right call as well. The only thing I wish I did was buy and change the transmission fluid while I was under there. I have no idea how hard the previous owner ran the car, otherwise I probably wouldn't change it for a while.

I will say you go beyond what is expected in answering questions. Thank you for the support. I'll definitely get with you about a fork if I decide to switch over to the zspeed master.

 

Ryan, I will be interested as I already installed the Wilwood Master Cylinder on my car ! Unfortunatly I guess you already sent me the pedal

 

Patrick, you're very welcome and I'm happy to hear you got it running well again. Hopefully that solves it for you perminently or atleast until you upgrade the clutch later

Greg, I'll have a new fork shipped out to you Monday with the modifications required to mate up with your Wilwood Master as we discussed.
Unfortunately I wasn't aware you had a Wilwood Master until today. Your 350Z Pedal Kit was shipped for Europe yesterday morning International Express.

 

You're the man Ryan ! Thanks !
I will keep you posted guys with few pictures of the RJM Pedal with the Wilwood MP !

 

Just finished my install, everything went well and the guide was clear and easy to follow. The results are amazing, so much easier to shift with a smooth feeling of clutch engagement allowing for easy hill starts and fast accurate shifts with no clumpiness from that terrible spring. definitely worth every penny if you like a good shift! Thanks RJM

 

And there it is! Done ! The RMJ pedal with Willwood MC:
Thanks a lot to Ryan ! Nice and available
A real better feeling with the clutch, let tune and test that now !

 

Mine is doing this as well, although not as badly as you describe. I notice that my engagement point keeps changing (getting closer to the floor) and so I keep adjusting the rod...now I am out of threads. But it seems to improve when the car warms up.

However this morning while driving to work, I decided to stick my foot under the clutch pedal and pull on it for 30 seconds or so. Viola, the freeplay at the top was gone and the engagement point was at least 1/2" or 3/4" higher up. It remained that way for the rest of the drive. Its almost too high now.

Is this the reason for the "helper spring" in the stock assembly? Because I was basically using my foot to perform the same function.

 

mx594 did you adjust the upper cruise switch each time to extended the clutch rod? If not the pedal would be against the upper switch stop and by threading the clutch rod out would start to depress the master cylinder to some degree all the time. The upper switch plate is intentionally designed NOT to be very stiff so that if one does over extend the clutch rod without adjusting the upper switch position the upper mount will simply flex upwards to stopping potentially destructive clutch damage.

All clutch rod adjustments should be made with the upper switch out or threaded in very shallow so it isn't holding the pedal down while setting the overall pedal height and friction point. There are still 3 main springs in the hydraulic system all working to return the pedal to fully up without need for a 4th. The clutch diaphram is the main force returning the pedal, followed by a return spring in the slave cylinder which pulls the throw out bearing off of the diaphram face when not depressing the clutch, and lastly there is a return spring inside the master cylinder itself trying to push the piston and clutch rod fully out again when not being depressed.

Now I think what is happening in your case is when you pulled the pedal up with your foot you were also flexing the upper switch mount upwards while doing so.

Now for why the pedal goes spungy. If the master cylinder rod isn't allowed to go all the way out to its fully extended position it doesn't uncover the fluid port inside that allows fluid to flow between the pressure side of the MC and the reservior. So what happens if this port is always held closed is that fluid can't move to or from the reservoir causing the friction point to rise higher as the car gets hot and fluid expands. Then in the morning when cold the fluid will have contracted overnight making the pedal spongy and the friction point very low until things warm up or as you discovered by forcing the pedal up against the upper switch that you opened the transfer port long enough to restore proper MC operation and the friction point immediately came up.

I would suggest going back to the install guide and reset the pedal height, get the friction point set back where you like it and then re-adjust both switches so that they just click plus a little more. However if adjusted properly neither switch should ever be depressed to the point where the white ruber bumper is hard up against the threaded body of the switch.

Hope that helps
Ryan

 

The above response is one reason why RJM Performance is such a great company. It definitely shows in Ryan's care for customers concerns.

 

Thank you, I will take a look at it and report back.

 

I just want to confirm that I am at 75% here based on the pics below. How does it look?

 

Diesel350,
Looks good and appears to be correctly set to 75% setting from the photos.

 

Ok great thanks, Is 75% optimal for a novice driver such as my wife, or should I lower it to around 50% to make the Z easier for her to drive?

 

75% is optimal as it will be easier to drive then 50% and is about the highest you can go on a stock clutch. The higher the AFP setting the easier it is to modulate and control the clutch. The lower the setting the closer it will feel like stock.

The actual percentage is meaningless as it is simply an easy way to describe how the adjuster is set.

0% is the same as stock. No change to the factory fulcrum length.
50% is simply 1/2 of adjustment range I built into my adjuster.
75% is where I recommend everyone starts as I found this to feel the best for the most customers.
100% is simply the maximum amount my AFP adjuster mechanism can physically move the fulcrum point (where the fork pushes from) on the arm in relation to the upper pivot point.

75% is simply a place to start as most will play around with this setting up or down to suit their own personal preferance in clutch feel or adjusts based on their specific engine and clutch setup.