charging AC

[86aggie]

AC was not cold. Used a can of A/C PRO, with their gauge and hose set up(I've had it for a few years). Got RPM up to 1500, recirculation on, full fan, full cold. Was able to get it to register @ 25 on the gauge, which matches FSM. Still wasn't as cold as I thought it should be, so I got another can and started loading it in.

Same set up, however, when I started, the needle stuck at 10 on the gauge. As I added coolant, it would jump up, then drop back to 10, jump up, and back down again. Ultimately, got it to 35, air at vents was cold. As the compressor cycled though, it would drop to 10 for a short time, compressor would kick in, take it up to 35, and as soon as it hit 35, it would drop back down to 10. I don't recall it cycling that quickly in the past.

What has your experience been?

 

[SteveH]

What center vent temps did you see (that you didn't feel were cold enough)?

A/C Pro appears to be R-134a - has your system been converted to that refrigerant?

 

[86aggie]

I didnt put a t-meter on it either time. The first was no cold air at all, the second was 'cool', but cold. Mine was converted over a few years back. My kids have been driving it for the past 9 years, until last fall, and weren't great about disclosing maintenance or repair issues. I haven't pulled the tickets to see when I had the system redone, I know it has a new compressor and drier.

 

[fj60dave]

a full charge when the a/c system is empty/vaccum'ed is three cans of r134a; you must use a manifold gauge and purge the lines. never use any refrigerant with any kind of stop-leak substance added. if your system has been open and you have lost the vacuum, it will never get the vent temps below about 57F.

The R134a wants an exact charge or less to cool/function correctly. If you over-charge (too much refrigerant) the system will hardly cool at all.

 

[Michael Hanson]

Hi, Change all o rings, vacuum and see if you can pull a vacuum. I have never had to put in more than 1-2 cans of 134 A. Remember it doesn't take as much 134A as R-12. charge on low side only. Also helps to put the can of 134A in Luke warm water. Mike