No Clutch pressure?

[Alex Datsun]

Well it seems something its stopping me from building enough pressure to move the clutch fork, i tried bleeding it out again and there was air bubbles which gave it some more pressure on the pedal but physically looking at the clutch fork minimal movement. its a brand new slave and clutch master but the pedal is kinda soft and never gets stiff problem is the entire time i drove the Z i always had a soft pedal so i can tell the significant difference. When i first started the car and put it in reverse it barely engaged and slowly stalled out, couldnt put it back into gear. So before i drop the transmission, i wanted to get some insight before doing so. Maybe pressure plate doesnt match throw out? Anyways to identify pressure plate?

 

this is clutch pedal not pressed:

 

pressed:

 

thanks guys!

[datzenmike]

There should be several mm or 1/16" of free play on the peddle before resistance is felt. Push down with your thumb. There should be a small 'wiggle room' before the master starts to work. If this isn't set right it will limit the slave movement.

[banzai510(hainz)]

So your saying you have both a new slave and master?????

 

one time this happen to me. I installed a new master in datto510s 521. We couldnt get pressure either.

Then I put my finger over the hole in the master cylkinder and told him to pump up the master till it finally shot out fluid.

 

You could do the same thing open the slave and try that. then lock it

Now when everything locked you push the master in and see small airbubbles then its a sign it could be bad also.

 

This is assumeing the t/O fork and trans is OK. Nothing really more to the system than that.

[kelowg]

Had same problem when i put in new master, air gets trapped somewhere. Unhook line at master and bleed it. Then the line down to slave,then again with everthing connected.

Took me several tries and still alittle soft.

[ggzilla]

+1 you must bench-bleed a new master before installing. If you didn't do that, then "Unhook line at master and bleed it"

 

Plus you need 1/16" play (mechanical). Push the pedal with your pinky finger to confirm.

[Alex Datsun]

small 'wiggle room' before the master starts to work. If this isn't set right it will limit the slave movement.

This is what i was thinking when i was bleeding it yesterday, i adjusted the rod and got alittle more movement so that was about it, my friend isnt a car whatso ever so he couldnt tell the difference.

 

I put my finger over the hole in the master cylinder and told him to pump up the master till it finally shot out fluid.

 

You could do the same thing open the slave and try that. then lock it

Now when everything locked you push the master in and see small airbubbles then its a sign it could be bad also.

 

This is assumeing the t/O fork and trans is OK. Nothing really more to the system than that.

 

i didnt quite catch the "everything locked push the master in and see air bubble", for the slave when i open it the fluid comes out perfectly fine.

 

+1 you must bench-bleed a new master before installing. If you didn't do that, then "Unhook line at master and bleed it"

 

I did that to get all of the old fluid out of the lines but ill try it again

 

 

 

 

So whats would the symptons be like if theres a mitchmatch in pressure plate to throwout?

[DanielC]

If you have not recently changed the pressure plate, or clutch disk, or throwout bearing, and everything used to work, I do not think anything inside the transmission bell housing is the problem.

First guess, you still have air in the hydraulic lines. Second guess, the master cylinder is internally bad, and when you push the clutch pedal, the fluid just goes around the piston in the master cylinder, instead of going to the slave cylinder. The pressure of the clutch forces this, and it may not show up, when you bench bleed the master cylinder.

 

Have some one push the clutch pedal while you watch the level of the fluid in the master cylinder reservoir. It should go down slightly when the clutch pedal is pushed down, and held on the floor, and rise slightly again, when the pedal is released. If the fluid level does not change, the master cylinder is leaking internally.

[banzai510(hainz)]

If the fluid level does not change, the master cylinder is leaking internally.

 

Youll see the tiny airbubbles come up from the master cyl. and the slave cyl will not move .

[Alex Datsun]

If the fluid level does not change, the master cylinder is leaking internally.

 

Youll see the tiny airbubbles come up from the master cyl. and the slave cyl will not move .

 

 

 

ooh ok i see what you mean now, dammit shoulda posted this is up last night before i did work on the dam car. The tranny I have now is a 280zx transmission compared to my doodoo 280z transmission but never confirmed exactly. Thanks guys the info is much apppreciated should be getting back to it again after work tonight.

 

edit: What would Symptoms of a bad slave would be, no movement,leaking,etc?

[ggzilla]

Bad slave would either 1) not move or 2) leaking. If it doesn't move it could be a bad master, bad slave or air in the lines.

[Alex Datsun]

Bad slave would either 1) not move or 2) leaking. If it doesn't move it could be a bad master, bad slave or air in the lines.

 

 

Ok i thought so cuz thats happened on my z31 way back when, it does move , no leaks, going to check the master cylinder tonight and then if thats fine ill try adjusting the rod some more. For the rod is their ideal spot that it should be or is it aslong as it has that little of freeplay?

[datzenmike]

Has to have about 1/16"

[Alex Datsun]

Worked on the Z for a sec to check everything, had my friend pump the pedal while i was looking at the clutch master. The fluid rises then goes back down without a problem but what i did notice is even trying to physically pull the clutch fork it will only budge a bit, im going to grab a clutch kit with a matching throwout and hopefully fix the problem or figure out why its not going into gear either way it looks like the transnmission is coming out tomorow night.

[ggzilla]

The fluid rises then goes back down

 

That is a problem. It should not rise in the Master Cylinder. It's a symptom that it is not bled properly or is a bad M/C.

[I'm BLUE]

Edit: --- looking at both your pics posted. It appears your steel braided clutch hose is either leaking or leaking at the sealing surface. I might be off but I have never seen a zcar clutch line with an exposed edge copper washer at the sealing surface. ( could just be a smaller fitting hose on the clutch line end itself that allows the copper washer to be "exposed". )

 

Bench bleed both master and slave cylinder. Air is trapped. If one does not bench bleed or lets a line go "dry" tbis is the result.

 

Manufacturers say its absolutely neccessary to bench bleed.

 

Also ... check for a restricted line or blockage.

 

As q last resort ... new and re-manned products can be "bad" right off the shelf!

 

I have done it both ways and bench bleeding requires less work in the end.

 

:)

[Alex Datsun]

 

 

 

That is a problem. It should not rise in the Master Cylinder. It's a symptom that it is not bled properly or is a bad M/C.

 

I thought it was suppose to go down and rise slightly as Daniel mentioned?

 

 

Edit: --- looking at both your pics posted. It appears your steel braided clutch hose is either leaking or leaking at the sealing surface.

 

Bench bleed both master and slave cylinder. Air is trapped. If one does not bench bleed or lets a line go "dry" tbis is the result.

 

Manufacturers say its absolutely neccessary to bench bleed.

 

:)

 

 

DTP you read my mind, i was talking to a friend last night to and mentioned we should bench bleed everything just to be sure since he is gonna help me drop the trans if neccesary. The ss line looks like it was leaking cause the picture was right after bleeding it, im going to remove the washer and bench bleed everything.

[poor-mans-720]

okay, This is along the lines of no clutch pressure. maybe somewhat relevant. (sorry to thread jack)

How can I increase the pedal pressure? Like make it a firmer pedal, a sportier feel? its in a 720 Z22 KC.

The pedal is just mushy... like no feedback. I used to drive a friends WRX that made my left calf twice the size of my right, just from driving. Used to walk in circles.

Don't need it that extreme. But I have the worst feeling clutch ever...

 

Also, i replaced all the clutch components on the 720, but i did not "Bench Bleed" is this what it sounds like? just bleed it on the work bench before install?

[banzai510(hainz)]

poormans 720

go to importrp.com and buy a daiken stage 1 clutch or to SPEC Clutch. for your vehicle.

 

as for alex, if noitn was changed before. its sucking in air, master or slave. Thats is it.

 

I have ha slave look good but after a few days it would suck in air(Taiwan) about YEAR OLD, DID A TRANS SWAP.

 

I got a Jap made on and got rid of proplem. But I have spares at home to trouble shoot this.

[Alex Datsun]

Dammit seriously? Cause thats the exact story of my slave and clutch master quite frankly and.once before on my z31. Ill keep messing with the hydraulics first until i get to a deadend.

 

 

[ggzilla]

Two get a calf-hurting clutch, get a "high-pressure" clutch cover, like a 750 lb clutch. And a new clutch hose. Old hoses swell, giving a mushy feel.

[datzenmike]

okay, This is along the lines of no clutch pressure. maybe somewhat relevant. (sorry to thread jack)

How can I increase the pedal pressure? Like make it a firmer pedal, a sportier feel? its in a 720 Z22 KC.

The pedal is just mushy... like no feedback. I used to drive a friends WRX that made my left calf twice the size of my right, just from driving. Used to walk in circles.

Don't need it that extreme. But I have the worst feeling clutch ever...

 

Also, i replaced all the clutch components on the 720, but i did not "Bench Bleed" is this what it sounds like? just bleed it on the work bench before install?

 

From November '82, Nissan 720s used a in line hydraulic clutch damper. It's mounted on the right of center on the firewall and has a bleeder on it. I have no idea what Nissan was thinking when it installed them.... maybe people who shouldn't drive complained that their feet hurt pushing the clutch down or something so they 'softened' the feel. Not sure how it works even but there is a rubbed puck inside and a piston that pushes into it. Remove and join the lines.

[poor-mans-720]

I hope you are right, and mine is still in the hyd. system. If so, I am pulling out my working lamp, and I am going out right now, to pull that little sucker out. You should have a Doctorate in Datsuns...

I am going to see what month my Datsun was made.

 

Well mine was made in May... So no diaphragm. Its, hard line from master cylinder to slave cyl. minus the 6'' of rubber hose at the end, near the slave.

[Alex Datsun]

Yay!!!!! So i swapped slave cylinders and had the same result... but i i adjusted the rod as far as it can go, go rid of the copper washer from the ss line, benched the slave master and tried again. Succuess finally alot more movement and way stiffer pedal now so i cant pinpoint on one thing since i did numerous stuff at once. I took a look at the previous and seemed to be ok. I didnt get to test it out cuz i ca start at this time since i have open headers.

 

 

Thanks ratsun family much appreciated from stopping me from doing something neccesary.

[poor-mans-720]

Thanks ratsun family much appreciated from stopping me from doing something un-neccesary.

 

Whoa man... hope that's a typo.

 

I am going to take my master off and bench bleed it today too, searched it out on the forum, got it figured out. And I'll let you know my results from just this. See if it doesn't fix my issue of a mushy pedal.

[Alex Datsun]

Whoa man... hope that's a typo.

 

oh yes it very much was a typo but now that i actually was able to turn the car since its in the middle of the day another problem has come up. It feels as if the clutch isnt fully engaging, i adjusted the rod some more and got little more engagment but it feels as if it "never lets go". I had a problem like this once before and i adjusted the clutch master rod and it fixed it but now it seems it cant be helped. Should i try bleeding it some more too see if i can get more pressure? or can it be something else?