After bleeding the clutch i am have problems getting it to build up preasure even though there is no air in the system

You should have bench bled the slave thoroughly before installation. Even tiny air bubbles in it will be very difficult to bleed out. You may need to take it out, bleed it well in a vise with a bleed kit and reinstall then gravity bleed the system with the other end open, then normal bleed to get remaining air out of system. Or, you have a leak in the system allowing air in. (check for that first)

So the clutch isnt didengageing? Check the inside firewall is there fluid on the pole going into the cylender? if so the master cyl is bad, check the slave for leaks also, and yes there is a nipple down there to bleed it it gravity bleeds, so fill it up and open the bleeder untill no air comes out, BUT MAKE SHURE you dont let the fluid container run out or you will be starting over :)

Don

Run the compressor until there is about 75 psi in the tank and turn it off at the pressure switch. Remove the black bleeder line from the pressure switch:
1. If absolutely no air comes out of the line you may have a bad start capacitor on the motor. Have it tested at an electrical or refrigeration shop or just replace it to see if it takes care of your problem.
2. If you get a short blast (five or so seconds) of air then nothing your pressure switch isn't letting the head pressure bleed off after the motor shuts off. This pressure has to be relieved or the motor has to fight the tank pressure when it tries to restart. Reconnect the bleed off line and turn the motor back on. If it starts normally, replace the pressure switch. If it struggles or won't start it is more indicative of a bad start capacitor.
3. If you get constant air flow from the bleed line the problem is with your tank check valve. This causes the same problem as above. Replace the check valve.

Clutches can be a pain, do you have fluid bleed out with no air bubbles coming out, if you cant get it to bleed it works best to raise the front of the car up with a jack or as high as you can get it within reason, doing this makes the slave cylinder the highest point therefore air will travel to the highest point making it easier to bleed and get all the air out. if you still cant get it to bleed after that try letting it gravity bleed for a few minutes and then try bleeding and if that dont work possible bad master cylinder. If this is a problem that developed and you have not replaced clutch slave cylinder the slave cylinder is probably the issue

It's a matter of bleeding the clutch system completely. You do need to make sure you don't ,have any leaks at the Clutch Master Cyl. or at the Clutch Slave Cyl or the line running between both, and that you don't have clutch fluid in the drivers compartment just below where the clutch rod comes through the firewall. That would of course mean you have to replace the Clutch Master Cylinder due to internal leakage.

This isn't so unusual, you'll have to pull up on the pedal by hand & pump it a few times to get pressure enough to properly bleed the system, or, you will have to start with bleeding the Clutch Master Cyl. first by loosening the line there & have someone push down the pedal, then before letting up on the pedal, tighten the line to prevent air from being drawn in. Repeat two times to get any air out here.

If your parts and lines are all in good shape then re-fill the resivoir & have someone to pull up on the clutch by hand if needed & then if necessary, use their hand to depress & pull the pedal a few times to try & build some pressure so that you can bleed the Clutch slave cylinder a few times to get all of the air out. After you've finished bleeding the system, the pedal should stay in the up position except when being depressed and you should have consistently even pressure when using the clutch.

good luck.

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sounds like the master cylinder is not properly bleed. make sure there is no air in system, thats the most common reason that it does not build up pressure, did the cylinder run dry?, if so, more then likely you have air in system, if not, you may need a new slave cylinder.

You may have to power bleed the system to get it to work and double check you got everything put back together.

ok now you said,the system was checked to be sure the refrigerant level was full . It could also be over full causing a over preasure shutdown. The compressor has a low and high pressure switch, that will disengage the compressor clutch if it senses a over or under preasure situation to protect the system.Did you check to see if the compressor clutch was Engaging and will it stay Engaged or disengage and keep cycling like that? you Will need to get the preasures on the high and low side of the compressor from a gauge manafold set and please record the outside temp. it will change the preasures in the a/c system than i can better help with the issue you have. also a/c will always work better if recirculated air is used, because it is already cooler than out side super heated air.

my name is ron and if you get the preasures for me i will be glad to check the preasures to My R-134 refrence card

Just a thought.....air will rise. If you put plenty of fluid in the clutch res... lock it down......and you put the bleeder valve higher than the reservoir....(tilt the wheel you are bleeding in the air) won't the air go to the top...........?????...just a back words way of thinking of it..........hmmm mtg

I have had some problems with that as well. Two things that it might be one is air in the lines. Make sure that the air is properly bled from both valves. Start with the bottom first. The other if you have the 91 300zx that was made before August of 1991 then it might have the first Master Clutch Cylinder which has a smaller bore than the upgrade made by nissan in the later part of 1991. The upgraded CMC has a larger bore and works alot better with Aftermarket Clutch system.

Your problem seem to be that it doesn't get enough fluid to make preasure for the clutch. When DOT 3 fluid gets warm it expands but loose density which means it cant supply the preasure need to hold the clutch. Getting air out of the system which will block the line or increaseing the size of the bore on the CMC you can get more preasure which should improve the status of your clutch.

Oh yeah don't forget about the Pedal Adjustment. That sometime needs to bew done as well.