is this a safe pressure for the ac?

[jblackburn]

Because the pressure was too low at the suction side for it to justify keeping the compressor running. A constant 25 psi is the bare minimum to keep it from cycling off again.

[erikv11]

Don't keep adding oil. the oil does not get evacuated when the coolant is removed.

[hanzbe420]

so when i buy another can just get the one without oil? sense i already put an 18 can that has the oil in it already? And when i evacuated the r22 some clear thick gooey stuff came out i am thinking that's the mineral oil in it or something? anyways i got as much out as possible i dint vacuum it i just drained it and refilled with the r134a. will it be OK?

[hanzbe420]

OK so today i put a refill can with 12 ounces of r134a with no additives. I found the best way to charge your system is to jumper the switch so you don't have to worry about it going on and off and all that stuff. Just jumper the switch and measure pressure and charge to like 35 psi. Replace plug. and your done. i revved it really hard and the compressor didn't shut of once. I have tried to do it before without jumper the switch and no matter how much i put in the car the compressor just went on and of. But when i jump the switch it always works when i fill it and put it back. so i suggest if your ever filling an empty a/c just jumper the low pressure port switch, just undo the harness and stick a wire to each medal lead in the harness, fill her up to 35. replace harness. that's it. Colder then an icicle. but i did notice with r22 it was allot colder. but its defiantly almost to cold on full blast lol. That will come in handy when its 100+ this summer. I thought i would have to shim the clutch but nope its fine. so all in all it took 1 18 oz bottle of ez chill by id. then another refill with no additives 10 oz can, you should have a little left out the 10 oz when your done. this is for 94 850 turbo.

[hanzbe420]

OK so a little while ago i popped on the gauge to make sure the pressure didn't change and that the system wasn't leaking. now it was charged to 35 yesterday, and now when i checked it this morning it was at 23-25 and when i revved the gas it only went down like to 20 but the compressor stayed running and it still blows air. I unplugged the low port pressure switch and the compressor turned off, so i no its no that. This was done with the same brand gauge just a different one. last night i took the glass cover off the gauge and i touched the pin. would that mess anything up. (lol i no stupid) Ill have to check it with the same gauge i filled it with. but i just thought it was a little weird cause i doubt anything is wrong with the gauge but you never no. i guess as long as it stays working then i shouldn't worry about it. But I am going to my pops later and i will check pressure again with same gauge i charged with. But all i did was turn the pin with my finger to 45 and let go it went back to 0. So i don't think that would mess up the gauge or would it? And it was pretty much about the same temperature give or take a couple degrees.

[erikv11]

Touching the gauge needle like you describe should not be a problem.

Was the system just mysteriously empty to begin with, or did you empty it for a service job, etc? You never posted anything about why you were refilling, or about troubleshooting etc, just "how do I refill?" So probably others like me assumed you knew the system was OK.

But if the system was found empty and you don't know why, well then almost for sure it has a leak. In which case it will not hold pressure, the freon will leak out again. On almost *every* 850, the evaporator core will fail. At least half of them out there, it already has.

So a likely scenario is the evap core has a leak, and will not hold refrigerant. It is a huge, nasty job to replace the core. But watch the pressure with the same gauge, that will tell you. If it is leaking and you want to try to fix it, then you will want to use a can of R134a with tracer dye, move ahead from there etc.

[hanzbe420]

Like i bought the car and the guy said it was sitting for like 3 yrs in the garaged. So when i went to do the a/c i cant remember if it was totally empty or what. I just no the compressor wasn't turning, telling me it was low. so i filled her. but it still wouldn't work. now this time i drained her compleatly. Got a can with oil and put her in, then another smaller refill can with no oil or sealers. And when i put that in it stayed running but i had to jumper the switch or no matter how much freon i put in it wouldnt stay on. So i jumperd it and it took about 35 psi. i went back to my dads and checked it with the same gadge it looks like it was about right maybe 2-5 lower. I will just keep checking it to make sure it doesnt drain. But i dont think there is a leak. Its been raining here in ct allot so i havent been able to fully test the a.c. But now the compresor stays running when i hit the gas hard it still stays on. So i guess its fixed for now i just gotta watch it for leaks. Bust as for your question i dunno if it was empty the first time i filled it but it probably was. after sitting for so long. And the reason i drained it before cause some one talked me into using r22 and that it wouldn't cause no harm. Then i drained that and refilled with r134a, but so far i guess its going good. when i rev it hard the pressure only drops a tiny bit not enough to turn off the compressor so i guess ill leave it alone for now. Thanks for your input.

[Bigblue]

You don't need to run the system to find out if it is full or not...With a cold engine, attach a gauge and check the pressure...The pressure should be a few pounds higher than the ambient temperature...Temperature/pressure tables are available by Googling...Example...If the temperature is 80 deg, the static pressure should be 86 psi...If the temperature is 100 deg, the static pressure should be 109 psi...If it is too low, refrigerant can be added without running the system by putting the can into hot water while adding refrigerant until the pressure equals the chart callout for the temperature you are working at...If the pressure is much higher when you check it, it has been overcharged which can result in damage to the compressor, (excessive clutch slippage and wear, etc,) cause evaporator leaks due to split seams, and probably produce unsatisfactory cooling...Some folks believe that if a little more refrigerant is good, then a LOT more is better...Not so...There is an optimum amount and it must not be exceeded...

When adding refrigerant, it is important to purge the gauge and hoses of air before puncturing the can and adding refrigerant...Do this by loosening the hose fitting a little at the can and allowing some refrigerant from the car's system to escape...This pushes the air out of the hose and fills it with refrigerant from the car's system...Atmospheric air contains moisture, especially on a humid day...Moisture in the system reacts with the refrigerant and forms acids that corrode the system...Also, the moisture can freeze in the expansion valve (or expansion tube, depending on the system architecture)...That will stop operation until the ice melts, then the cycle will keep repeating, on, off, on, off, etc...

Do not carry a can of refrigerant around in the trunk...On a hot summer day it can get to 150 deg in a parked car...A can of refrigerant at 150 deg is at a pressure of 265 psi and might burst...

[hanzbe420]

OK today i went outside and was running the ac on without turning the fan on and it was blowing nice cold air. so i figured this didn't waist gas sense the fan wasn't on. But i was wondering if this would freeze the expansion valve? cause i turned on the fan and it kept cycling on and of and i just added r134a so either there is a leak or the valve is frozen. would running the ac on without the fan cause the valve to freeze, temporary making the compressor not work till it melts or how does this phenomena happen?

[jblackburn]

The fan only turns on when the high side pressure builds up to a certain amount (meaning that refrigerant is really, really hot). I dont know the number, but if the compressor is cycling, it's not reaching that high pressure required for the ECU to turn on the fan.