The reason some say to add the refrigerant with the can upside down is to allow the lubricant to be drawn intot he system. If there is no lubricant, and the refrigerant you are adding is not a blend, then it really doesn't matter what orientation the can is in. While it is true that all refrigeration happens on the low side, this is only half of the heat pump cycle. The other part is where the heat gets released through the condesor, and this is where the critical pressure lies. The correct pressure for an AC system is based upon the temperature in front of the condensor. You slowly add the refrigerant, and watch both the low side and high side guages. The low side can remain a fairly low reading, but you are getting maximum cooling when the high side is charged to the proper level. At the correct point, the coolant liquifies as if cools in the condensor. If the pressure is to high, it liquifies to easily, and doesn't vaporize properly in the evaporator. To low and it fails to liquify and so instead of undergoing a phase change, it simply undergoes a pressure change when traveling from the low side to the high side. It reallty takes some experience to correctly diagnose AC systems, but most problems are simply a matter of low or high pressure.

 

Nappers:

A lot of the time, especially with R134a systems, the condenser needs a healthy draft of air to work properly. I think your reduced cooling was most likely a result of the fan clutch going bad on you. Check that first.

 

i would suggest buying and inserting the A/C special lubricant and the refrigerant seperately...do recommended amount of lubricant first...then refrig.
most professional commercial refrigerant A/C shops do it this way...lubricant quantity in system is critical...too little and compressor self destructs...too much lubricant affects coolant flow and heat exchange efficiency

 

I will check the pressure tommorow after training (weaponless defense yay ) and let you guys know.

Thanks.

Aaron

 

On ym earlier posts, I didn't recall seeing a year posted, so the information I gave was just to be safe, in case it was a freon system. Repairing regular R-134a systems is somewhat easier, since there is no red tape to deal with. My previous statement still stands, checking the low side alone means little. You need to monitor both the low side and the high side, and you need to know the temerature at the condenser.

 

Dammit, everyone is right. the guy with cans that said charge upside down must have oil mixed with the ref. oil won't go in as a gas. My aero had low side port on accumulator, would it then be ok to charge liquid? I am always nervous about charging liquid into the low side.

Ken

 

Yes, you can charge it on the low side as a liquid, but my advise is, add it slowly. Again, I suggest useing a manifold guage set, since the results are so accurate. But just so long as you add slowly and don't overcharge it, you are doing good.

 

I will check that and get the pressures and get back to you. I've been on nights and too lazy to go out in the pouring rain and snow to check.

Thanks for the responses and I'll get back with ya all.

Aaron
Nappers

 

Okay guys,

I checked the pressures with the little gauge that came with the kit.

The pressure bounces between 25psi and 45psi, the intervals between 25 and 45 is about 5 seconds or so. The clutch makes quite a loud click when engaging. I checked my GMC and get the same results only the GMC is not as loud. Like I said before, everything seems to work well, but the clutch is louder than before and "seems" to have to work harder.

The van was warmed up and A/C had been running a while and blowing cold air (didn't check temp though). There was two different ports, a smaller one and a larger one, the gauge would not fit the bigger one only the smaller one on a round gizmo with a couple of tubes coming out of it, I had to remove some sort of controller to get to the nozzle.

Thanks for any input guys. You sure saved my skin in the past.

Aaron.

 

are the above pressures okay and maybe I need a new clutch? or just take it in and have it serviced.

Thanks in advance

Aaron

 

That is within the normal range. I would wait till early spring and see how it is doing then. Most shops then run pre-summer a/c deals then.

 

Thanks for the input. I will wait. I think the clutch is making the noise, maybe it's just louder than what I remember, I also freak out a lot . "WHATS THAT NOISE???????" The little woman goes???? uh....what noise. LOL.

Take care.

Aaron