Clutch pedal is weak

[BadQ45t]

I got into my Z for my annual oil change with Amsoil extended after a few weeks of not driving the car. Anyhow, noticed the clutch pedal was a bit weak, just not as much pressure as it would normally put back into my left foot. Today I went to move the car and the car didn't seem to want to go into reverse, a double clutch got it into gear but still it feels like the pedal has very little pressure.

I am sure something is wrong, is there any type of spring in there or is all hydraulic? Is this likely to just blow up or could I drive it 400 miles to my mechanic I would normally want to fix, or should I get it done locally? What do you think is wrong??

[themadscientist]

It can happen. Check your clutch reservior for fluid. I am betting it will be dry or very low. Next figure out where it leaked out. Either the master cylinder leaked out the back (look under the dash where the pedal pushes the piston) or the slave cylinder leaked out the piston end (gonna have to climb under the car for that.)

[BadQ45t]

Thanks for the quick response. I am going to assume (I have owned this car for 30 years and today for the first time looked to where the clutch fluid is) it is the little small container behind the windshield wiper. It is completely full as are the brake and power steering fluids, checked all of them. Also, no fluid inside or outside the car that I can see, carpet is dry.

So assuming that little guy is the container should I put more in, it is up to the metal, what do you put in there anyways, DOT 3 brake fluid?

[G-E]

Yes, dot3 brake fluid is right... the leak is the main issue, that fluid went somewhere

My first suggestion is to get under the dash, peel back the padding/carpet and see if the fluid is leaking into the cabin at all, and see if you can see any paint damage on the engine side below it, at least you can eliminate the damaging part first...

Secondly you may want to replace the clutch slave on the trans, a rebuilt is like $20 so it's cheap insurance

[evildky]

It's also a good idea to replace the clutch slave and master as a pair, they are likely both 30 years old and if the seals have began to allow fluid to bypass at one the other won't be far behind. and being an 84 it has the damper inline which has it's own bleeder which is prone to rusting and breaking off, so if you do replace the master and slave you'll want to check the bleeder on the damper, if it doesn't open you can bypass it with a rear brake line.

[BadQ45t]

Okay, so the canister is the one just in front of the windshield wipers??? That is full, so I suppose if it is losing fluid it is minor, but I will search for any signs. So if this is fluid leak should I try to top off that little guy???

The clutch has been completely replaced at 130k so it is pretty new. However, if I have to crack the whole thing open I will probably do a final rebuild on it.
So 2 questions,
1. Should I upgrade to anything better than OEM for a NA? Stillen etc.
2. Can I top that off and drive 400 miles to my mechanic in LA that has done Z clutches thousands of times?

Thanks guys!

[BadQ45t]

okay, so I called my old trusty mechanic (Z Expert in Los Angeles, worked on my Z for more than 20 years) and he said "you driven it much lately". Nope, the garage queen has been mostly sitting. Answer, pump up the clutch 50 times with the motor running. When I got in it this PM the clutch collapsed to the floor..50 pumps and it is working again as normal. So my plan is get it to LA and do a "final" rebuild on it. Final means, like when I die one of my nephews doesn't have to rebuild it again .

There still no missing fluid, the canister was at the top (I put about 2 tablespoons in for good luck) and then it was normal again. I think it will make it 400 miles south, I also need to get a new fuel sending unit which Z Expert has in stock from 1999 and knows how to replace without dropping the tank.

[evildky]

If the clutch totally dies you can start the car in first gear with the pedal depressed and rev match shift, first gear downshifts are tricky and any stops you make mean starting the car in first all over again, not fun but doable.

If it acted up I'd plan on replacing the master and slave, the parts are cheap and it's not that big of a job.

[BadQ45t]

Thanks, I used to do that to show off how you didn't need the clutch....Checked it again this AM and still good, but I will probably redo the whole thing next run to LA, thanks for the help and suggestions.

If I did redo the clutch would you go OEM or upgrade to something stronger? The car is not at all mod'ed other than a nice catback exhaust, timing advanced, K&N filter and perfectly tuned up.

[evildky]

The stock parts are fine and to my knowledge there is no upgrade for the hydraulics other than deleting the damper, the clutch itself if it's not slipping it'd leave it alone. If it's time has come stock replacement for an unmodified driver should be fine.

[BadQ45t]

Thanks Evil and GE, appreciate your help on this. Tried it tonight and still nice and firm thankfully. I need to get a few other things done so I will leave it to my mechanic's judgment if the whole thing needs to be rebuilt or just the master, he doesn't do work that is not necessary.

[G-E]

If you have car ramps, you can change the slave yourself in about 15min, it's easy to access on the passenger side of the bellhousing, 2 bolts and the fluid line

If you just did that and had someone help you bleed the whole system pumping the pedal and adding fluid to the master, I'm sure you'd restore the functionality

While you're doing that, you can remove the clutch damper block if you haven't already, that makes it easier to bleed, and pedal feel will be improved... to do this you can use a good z31 rear inner brake hose, and bend the hardline to be a little closer by hand

Removing points of failure is always a good thing

[Aegis156]

Wish I had known that when I replaced my Master and slave cylinders.

[BadQ45t]

Turns out the master cylinder was completely fried. I am not a DIY'er so I had my mechanic do it. I was surprised that the Nissan Dealer had a brand new unit to replace it with, thankfully it works better than ever now.

[Aegis156]

I replaced both the master and slave for the same issue. Though first I ripped the master apart cleaned it and put it all back together. the cup shaped gasket at the front end had shrunk a bit letting the fluid bypass back into the reservoir. bought both units for a grand total of 40 bucks tax included.

[BadQ45t]

It was a little more than that from the dealer but it was a few hours of labor. I have no time or inclination to do work on my car, I would rather be riding my bike or playing X-Box...my dad said do what you do well and pay others to do what they do well

[Aegis156]

LOL

Mine always said to stand on my own 2 feet and help those who can't

[BadQ45t]

Given that I have zero understanding and I glaze over when I read the service manual it was best that I had someone do it. Never mind the talent or inclination but I just do not have the time to do this type of job.

I used to change the oil and do tune-ups on my first car a 1977 Toyota Celica but once I got the Z my days as a shade tree mechanic were over. Luckily I can afford a proper mechanic.

[Stuckonthedock]

While you're doing that, you can remove the clutch damper block if you haven't already, that makes it easier to bleed, and pedal feel will be improved... to do this you can use a good z31 rear inner brake hose, and bend the hardline to be a little closer by hand

Removing points of failure is always a good thing

Is there a write-up on the damper deletion? I have to bleed my clutch tomorrow and may as well do that while I am there.
TIA!

[evildky]

clutch damper deletion
http://z31.com/clutchdamperremoval.shtml