Weird clutch actuation problem

Engine, Transmission and related drivetrain.
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Chadsinto510s
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Weird clutch actuation problem

Post by Chadsinto510s »

To begin with the clutch slave and master have been replaced in the last year or less with LUK parts. That doesn't mean something hasn't gone bad but just there as an FYI.

So about 2 weeks ago my car stopped wanting to go into gear. It's acting like the slave isn't pushing on the fork far enough. The weird part is this only happens in the morning when it's cold out. By the time I get home in the afternoon it's fine or needs a couple pumps and it starts working as it should. The having to pump it a few times lead me to bleed the system this past Sunday. I noticed no air bubbles coming out but it was hard to see as I had to do this on the ground with 1 wheel up on a curb. All worked fine afterword. Test drove twice and figured I was good to go. This morning, same problem. The clutch pedal feels like it's doing it's job but the car won't go into gear. Even with pumping.

Anyone ever had this happen before? Where to start?
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Chadsinto510s
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Re: Weird clutch actuation problem

Post by Chadsinto510s »

Further info:

Originally tried to start the car with the clutch pushed in and in first gear and the car would try and move.

I made sure the clutch pedal rod was properly adjusted. It was a little more slack than it should be.

Tried the same test with the clutch pushed in and it did the same but not as strongly (maybe?). Shut the car off and tried again and she fired up no problem.

I DID notice though, that when first releasing the clutch I can feel something, lets call it a vibration for lack of a better, but only in first gear. It does not happen then the car is shut off or when shifting to any other gear.

Ideas anyone?
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datzenmike
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Re: Weird clutch actuation problem

Post by datzenmike »

Is the clutch reservoir full?

Does the clutch reservoir need topping up? or is it using fluid?

When the clutch master was replaced was it 'bench bled' first?
"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs
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Chadsinto510s
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Re: Weird clutch actuation problem

Post by Chadsinto510s »

datzenmike wrote: 16 Jan 2025 07:47 Is the clutch reservoir full?

Does the clutch reservoir need topping up? or is it using fluid?

When the clutch master was replaced was it 'bench bled' first?
Res is full. No puddles under the car and dry firewall. I did not bench bleed it but I did gravity bleed it through 2 res refills before pedal bleeding it.
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Not Now
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Re: Weird clutch actuation problem

Post by Not Now »

That's a strange one since it's been working for a year. I would guess there is a leak somewhere. Did you pull the rubber boot back on the slave and look for wetness? I've also seen the pivot ball that the clutch fork mounts to break before, that car struggled to go into gear. Can you have someone operate the clutch while you lay under the car and see if everything operates correctly?
datzenmike
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Re: Weird clutch actuation problem

Post by datzenmike »

Check the carpet up under the dash for wetness.

Is the slave push rod adjusted? Has the lock nut loosened?


The slave push rod should be capable of moving 1.18" when clutch pedal is depressed. Check this when cold in the morning when you usually have this problem. If moving 1.1" then not the hydraulics.

There should be no more than 1/16" of play or looseness when the pedal is depressed with your thumb before firm resistance is felt. It's important that there be SOME play just not too much.
"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs
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Chadsinto510s
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Re: Weird clutch actuation problem

Post by Chadsinto510s »

Not Now wrote: 17 Jan 2025 09:04 That's a strange one since it's been working for a year. I would guess there is a leak somewhere. Did you pull the rubber boot back on the slave and look for wetness? I've also seen the pivot ball that the clutch fork mounts to break before, that car struggled to go into gear. Can you have someone operate the clutch while you lay under the car and see if everything operates correctly?
It is weird but stuff fails. I have not pulled the boot yet. It "appears" dry from the outside. The pivot ball hadn't crossed my mind. Those things are kinda burly, how would one even break that? Having someone operate it while I look and get some measurements is on the list for this weekend. Thanks for the ideas.
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Chadsinto510s
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Re: Weird clutch actuation problem

Post by Chadsinto510s »

datzenmike wrote: 17 Jan 2025 12:03 Check the carpet up under the dash for wetness.

Is the slave push rod adjusted? Has the lock nut loosened?


The slave push rod should be capable of moving 1.18" when clutch pedal is depressed. Check this when cold in the morning when you usually have this problem. If moving 1.1" then not the hydraulics.

There should be no more than 1/16" of play or looseness when the pedal is depressed with your thumb before firm resistance is felt. It's important that there be SOME play just not too much.
The car has no carpet so that was an easy check. It's dry inside too.

I forgot to mention this car has a ZX 5 spd so no adjustment down below.

I'll measure movement this weekend.

There was maybe 1/4" slop in it. Excessive but it has been working just fine until recently. I adjusted down to what you've described. It seems less of an issue but still persists.
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Re: Weird clutch actuation problem

Post by datzenmike »

Check that movement early in the day. Again 1.1"
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Chadsinto510s
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Re: Weird clutch actuation problem

Post by Chadsinto510s »

datzenmike wrote: 19 Jan 2025 18:08 Check that movement early in the day. Again 1.1"
I did. I have vid but can't get it uploaded. Movement is in spec. None of this makes any sense.
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datzenmike
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Re: Weird clutch actuation problem

Post by datzenmike »

It can make sense.

We've eliminated everything from your foot to the clutch arm as being at fault. What's left? well everything out of sight... the pressure plate and or the clutch disc. If the disc is damaged or de-laminating it could be rubbing the pressure plate or the flywheel. I've had one of those coil springs in the clutch disc drop out and jam in the diaphragm. Diaphragm finger broken/damaged?
"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs
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Chadsinto510s
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Re: Weird clutch actuation problem

Post by Chadsinto510s »

datzenmike wrote: 21 Jan 2025 08:24 It can make sense.

We've eliminated everything from your foot to the clutch arm as being at fault. What's left? well everything out of sight... the pressure plate and or the clutch disc. If the disc is damaged or de-laminating it could be rubbing the pressure plate or the flywheel. I've had one of those coil springs in the clutch disc drop out and jam in the diaphragm. Diaphragm finger broken/damaged?
Yep. Next step is pull the tranny. I'm just waiting on my buddy to clear his rack so we can go after the issue. I hate no longer having my own equipment... :x :roll:
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Chadsinto510s
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Re: Weird clutch actuation problem

Post by Chadsinto510s »

Problem solved! Turns out a spring from the clutch disc fell out. Surfaced flywheel and new clutch and she's all good! Thanks for the help everyone!
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Not Now
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Re: Weird clutch actuation problem

Post by Not Now »

Nice!
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