A/C not blowing cold

My A/C is blowing cool air but not cold air. It needs to be colder.

-The car has 253K on it (7K with the engine rebuilt)
-The coolant is R12.
-I can only check the low side pressure with the gauge set I received from autorefrigerants.com (also ordered stop leak and es-12a)
-The low side w/ engine off = ~74psi, with the engine on it runs at ~35psi.

The condensor to evap line (thin line) is warm to the touch. The evap to compressor line (thick line) is cool to the touch.

I have not touched the coolant system since I got the car @ 111K miles.

I’m wondering if something is wrong with the evap core? Any help would be greatly appreciated as I am in Sacramento and it’s hot as hell here.

I am also having the same problem. And from what people are telling me and from what im reading is that i should recharge the A/C. Meaning filling it back up with freon (R12 and i was told Freeze 12 works also). You need a license to buy R12, but Freeze 12 you do not. The difference is, that R12 has a chemical in it that is known to pollute the ozone, and Freeze 12 is another form of R12 but without that chemical. Anyway, good luck and i hope this info helps.

My concern about recharging is that my Haynes manual doesn’t state a damn thing about the proper PSI range and I’ve seen a number of posts where the PSI ranges are not cited consistently. With my PSI at 37PSI on the low side, A/C full on, it seems as if I fall within the ranges people have been saying are proper on here; however, at autorefrigerants they say don’t go over 60PSI but they don’t say specifically if that is with the a/c on full blast or with it off.

I already have ES-12a if I wind up needing to recharge.

My condenser fan works fine. The compressor runs when I turn on the air recycle option. Can any one tell me the proper PSI range on the low side with the A/C running?

Help appreciated!

EDIT: The compresser clutch IS engaging. I visually confirmed that it is spinning when I turn on the a/c switch (which also has the loud click from the relay working). I’ve sent an email to autorefrigerants.com because I think they sent the wrong stinking gauges. I ordered the r12 set but the set I have only has connections which work on the low end so there’s no way of knowing the high end PSI. If I get that resolved it should help debugging my problem. I don’t want to add coolant with out knowing that detail.

there will never be a set psi at which your ac will be working at its most efficient cuz humidity and ambient air temp all play factors.

35 seems a little low, but if it was a chilly day out would be perfectly normal, i would wait for the high side guage to come in to make a move

I had to change my expansion valve. works awsome now.

It turns out that the gauge I was sent is supposed to be “standard” for an R-12 system. I was told that the high side sometimes needs an adapter. My high side has a smaller nipple than the low side. Does any one know what the hell this adapter would be called or what the part number is someplace?

where in cali are you? i might have wat you are looking for

Sacramento…looks like it’d take a hike to reach you but if you have an adapter for the high side nipple that’ll make it the same size as the low side, so that I can use it with my gauge set then I’m all ears…:bowdown:

Well, I survived last summer and this past winter. My work was stalled due to a chronic injury. Any way, I got the fitting for my gauges a while back. I just started messing with the system again as we’ve had a few days in Sacramento that were warm enough to warrant A/C use.

When I observed the pressure on the high and low side last fall, both sides appeared to fall within the proper range. The blower works at all settings. I just took readings today of the PSI. the low side would cycle between 26PSI to 48PSI. The high side was stable at 70psi. This was with the A/C on and blower turned all the way up.

The compressor was kicking on for about 18seconds which was when the low side pressure would go from 26 to 48psi. I’ll keep posting as I diagnose this nuisance. Suggestions are always welcome.