Reading older posts in this thread, looks like this was discussed already that guys have done it. Well I gave it a try. It's probably just the fluid, need to use higher boiling point like dot 4 or higher. Looks to say dot 3 on the reservoir cap.....fail.

Edit: I just bought some Super Blue ATE liter fluid for a nice brake and clutch flush I'll have some shop do (idk how to do this stuff lol).

radiohead369.....THANKS.

Can you believe the stealership wanted to charge me 1700 (with engine being replaced) or 2500 (after engine replaced), for a new clutch! And they only brought up the clutch issue because I complained about the pedal. They told me the clutch was worn down to the RIVETS like in JUNE LOL. I'm in september now, not a single problem, no slip (except for the pedal sticking). Freaking bastards.

 

I have posted on a bunch of similar topics. I have replaced the clutch master cylinder with a Dorman oem style replacement which was an easy job. I have replaced the clutch slave cylinder TWICE. The first time was with an inexpensive Chinese made Dorman unit, the second was with a nicer Taiwan made Wagner part. It's an even easier job. The hardest part was bleeding the system which could be tedious getting all the air out.

With that being said. My clutch pedal was still sticking intermittently especially on hot days above 90 and driving at least 20mins city/suburb driving. What best made a difference and eliminated my problem 100% was the "clutch pedal freeplay adjustment." Where you get underneath the pedal assembly, loosen the nut to the clutch master cylinder rod and turn clockwise (eyes pointed toward the front end) between 1-3 turns. A quick search will show a great illustrated thread about it. Do that first before you start replacing your clutch slave and master cylinders!

While you may not have to replace your cylinders I do recommend bleeding the brake and clutch especially since you've taken the time to raise it. You might as well put it on stands and do the work! The clutch fluid gets really nasty that you may indeed have to take the reservoir off and clean it manually. Here's a tip for bleeding. Get a cheap 1 person bleeder bottle at an autoparts store and bleed it after a full gravity drain. What originally took 20mins with the conventional 2 person way took 4 or 5 pumps of the pedal using the 1 person bleeder. Hope this helps!

 

Thanks.

Yeah seems first its fluid, possibly being old, or just too low of a boiling point (need Dot 4).

If the fluid has been bad a long time, it would probably kill the slave and/or master cylinder.


Considering how my fluid wasn't too bad of a color, and it only happened in high heat or excessive use, it seems to be more of a boiling point/old fluid problem. I'll get the flush sooner or later and post back.

 

i did some long spirited driving today, its been awhile since i've tried to take it easy on the 'clutch' lol.

car feels great, very fast, powerful, the shifts pound down, no slipping. i did a lot of engine braking and high rpm shifts the works. and the pedal is fine. granted i wasn't in high humidity, but it held up very well with how i was trying to heat it up.

looks like it was the fluid that was the problem. feels great.

 

Yeah, you're in Jersey just like me. So you've noticed the problem has totally vanished? It's because the outside temps are now cool! The problem will return next summer lol. I've used everything from oem, ATE Superblue (twice) to Valvoline synthetic brake fluid. I've changed the clutch master cylinder once and the slave twice. It doesn't matter. Same result. I've gone through 2 summers in denial. You're not gonna boil the fluid on a stock car driving on the street on a daily commute. What really needs to be done for starters is to adjust the clutch pedal freeplay. It takes less than 5 minutes and it will at least take the slack out of the clutch pedal. The freeplay directly affects the way the clutch master cylinder displaces fluid and when the temps get warm enough to affect clutch fluid expansion and contraction it is noticeable by the soggy clutch pedal. Maybe 2 turns is all you need. It can be reversible if you don't like it. Make sure the lock nut is tight so the clutch master rod doesn't loosen on it's own as well. Good luck!

 

jerrrsey. yea yaee. -ice cube voice- LOL

i've also used WD 40 on the pedal and that helped. this seems to be the slightest tension issue. if the pedal mechanism is just too tight, or the fluid is just too 'squishy' lol, the pedal sticks. very touchy. as long as its nothing serious i'm good, though it is annoying.

 

LOL @ Ice Cube voice. Oh yea, I've done the WD40 thing and it worked for a short time. Like I said you probably won't have to worry about it until it gets hot again next year lol. But you're not listening. Here's a link that will show you how to eliminate that soggy pedal feel and actually make the car feel more expensive again. The key is to turn the clutch master cylinder rod maybe 1 or 2 turns or so. Do not overdue it. It will remove the remaining slack off the pedal so the cylinder can do it's job better despite thermal expansion/contraction of the fluid. Takes 5 minutes and is reversible. http://my350z.com/forum/engine-and-d...ent-point.html

 

Thanks! I'll have to check it out.

 

This is a common problem with our clutch system. If the system flush doesn't provide a permanant fix may I suggest looking into replacing the oem clutch line with a stainless steel one. They are for sale on most Z/G performance part websites and are pretty cheap. I went through this last summer after upgrading my clutch/flywheel and someone on here suggested replacing that line due to it having a tendancy to swell from heat, causing the pedal to feel mushy and/or not rebound fully. I guess this is comparable to what happens with oem brake lines during hard trackday abuse. I swapped the line and was pleasantly supprised with the results.

 

Yeah I was actually thinking the same thing today, my thinking was that maybe some how the humidity goes thru the lining? Either way yes new lines is a good idea.

 

I just wanted to revive this dead old thread and mention that two years after doing the slave cyl. replacement, the problem is back... It has done it a few times in the last month. Twice when stopped after cruising at over 100 mph for many miles, and a few times in stop and go traffic. Normally neither of these would present a problem. definitely seems to be heat related - probably due to the proximity to the exhaust.

I'm going to try a flush first since it has been two years, but then perhaps a better clutch line and master are in order.

BTW, I have 150K on the OE clutch itself at this point with no slippage.

 

I have an 06 rev up and just had new clutch and lightweight flywheel installed. My problem is that when i release my clutch it will disengage but only partially come back up and have to pop it the rest of the way up with my foot. Any ideas?

 

A couple things.
1. Heat wrap on clutch line is missing and causing the rubber line to expand. Ignore if you have a SS clutch line.
2. You have air in your clutch line. Bleed it.
3. Last is cylinder related. But if its coming up. Doubt it. You may also need to adjust the clutch pedal as I know aftermarket clutches can be different on peddles.

 

Normally when the clutch pedal stops returning it is sometimes a fluid issue but most commonly the master cylinder is getting weak. It has been an issue for a long time on these cars G35, 350Z (same master)
Fluid flush may cover up the underlying issue for awhile but will eventually come back.

The reason the pedal only comes up partially is because on the return stroke the pressure is leaking by the cylinder seals and fails to push the pedal up.

You can either replace it with a new stock unit or get one of our upgraded master cylinder kits, We have them with Wilwood masters and Now with Tilton master cylinders
Both kits come with a Stainless Steel Flexible clutch hose and you can add our insulated short hose which is highly recommended esp on cars with HFC or headers/downpipes as the heat is a huge issue with these set-ups.

Both work very good on these cars and make bleeding the system MUCH easier.

ZSpeed Tilton Upgrade


ZSpeed Wiwood Upgrade

 

picture of the insulated short hose?