240SX Master clutch bleeding

[Abhiker]

I'm having a problem bleeding the line to remove the air. It seems that only when there is back pressure (or suction) on the line to the slave will the hydraulic fluid go into the master cylinder from the tank. Only if I put my finger over the discharge port of the master cylinder and draw the plunger it pulls fluid. Is this normal or should it flow freely from the tank everytime in pump the clutch? I'm wondering if the Master cylinder is not working properly?

[nicknasser300z32]

it wont necessarily pull fluid everytime.. as long as your gaining pressure and have the air all out of the lines your clutch should disengage and engage properly.

[Abhiker]

Problem is it's not pulling fluid at all to push back into the system to fill the lines. Unless there is back pressure no fluid moves.

[nicknasser300z32]

wait so when you pump it up and release all the air and fluid comes out? but no fluid rushes in to fill the lines?

[Abhiker]

I can't pump it up. I put fluid in the tank and with out the discharge line on it I pump the cylinder no fluid comes out! But if I put my finger over the discharge port causing a suction on the cylinder when I draw back on the cylinder it only then pulls fluid from the tank and then when I push the cylinder back in, then it discharges the fluid. It's almost like there is a negative pressure flap in the master cylinder for drawing fluid out of the tank. I was wondering if this is right or is the cylinder screwed?

[nicknasser300z32]

oh no it needs the back pressure build up in the line going to the slave for it to push fluid in and build pressure but if you still cant get it to bleed the air out with it hooked up to the slave then you might wanna look into getting a bleeder from your local autozone or napa or somewhere to pull the air out..

[Abhiker]

So your are telling me the master is working all right I just need a vacuum to pull the air out of the line by the slave and the fluid down the line from the master, causing the negative pressure?

[nicknasser300z32]

yeah that seam like the problem unless there's a leak somewhere in your clutch system but i cant diagnose that from here, i wish you best of luck trying to get it bled though i know haw frusterating that can be me and my friend have done almost everything to his 91 laser and we found his master and slave to be bad on top of the clutch taking a poop lol, hopefully neither is the case for you

[Abhiker]

Problem solved. I jacked up the front end completely and preloaded the fluid into the cylinder. I hooked it up and locked off the bleed plug. Pumped it up and behold it pressurized. So I had my son pump it and hold the clutch while I added fluid and bleed the line. So it all works now and I drove it around the block, works great. I know there was an issue with the fluid and air in the line but AAMCO what me to replace everything even after I told them my issue was most likely the fluid. The clutch engage cold very low and when it was hot out it engaged high and rode the clutch making it slip. Either there was lots of air in the line or the wrong fluid. Thanks for your help.

[nicknasser300z32]

welcome!!! lol as long as there's more nissans running the streets i'm happy haha