I just charged up my A/C on my 1999 Civic HX and my 2005 SXT. Started at 2 pm finished both vehicles at 3:40 pm. Lots of idling and cycling, plus it takes a lot of time to vent gas from a can tap and 12 oz R134 cans.

I used my $69 ebay Neiko Pro A/C Manifold gauge to charge and check my A/C. It’s an inexpensive but great quality enough kit to get the job done. Not as expensive as a Yellow Jacket but it does the same job. Check out my reviews of it on Amazon, by Jesse69.

Also check my Jesse69 reviews of this other stuff:

Initially, when I tried to charge my Honda A/C, I lost a lot of R134 from the high side from connecting too much from defective Interdynamics A/C manifold gauges. Finally got it fully charged with my Neiko Pro gauges. 36 psi low side with the high side at 210 psi, 90F outside inside air center vent blowing 55 F. It’s now cool enough but not a dreamy 39 F. But my Honda’s high side should be 240 to 300, so my compressor is not fully compressing anymore?

Anyway, the funny part is my 2005 SXT A/C. When I first connected it the low side it read 40 psi – too high. Then waiting awhile it dropped to 32 psi. So on a 90F day [my Kestrel 4000 read 89.2F], the low side should be 20 to 35 psi and the high side should be 290 to 380 psi. I took my time and charged it to 36 to 35 psi low side. When steady, my high side read 345 psi.

Now this is where it gets funny, while idling and waiting for the pressures to settle, sometimes my low side would suddenly go up to 60 psi, at the same time my high side would drop to 200 psi. Then this would cycle off and the low side go back to 32 psi and the high side to 345 psi. <- So does anyone know what’s going on with this?

And when I removed my gauge set, I turned off then disconnected my high side, closed the can tap, then vented some high pressure into the center system. Then closed the high side and vented the center high pressure to the low side by opening up the low side valve. Then closed the low side valve but the low side pressure went up to 40 psi. Repeated cycling high side to low side until it went to 150 psi. Quit cycling to low side because I didn’t want low side pressure > 40 psi. Then I said screw it and disconnected everything and vented the R134 from the gauge set. I hope I didn’t screw up my SXT’s A/C now, did I?

Results? Saved $140 charging A/C myself than having my cheapest auto mechanic do it. Honda A/C at 90F, cools the interior down then blows to 52F. 2005 SXT at 90F, before charging middle A/C vent blew at 55.8 F, now it blows at 50.6F. I’m a little bit disappointed that it’s only a 5F improvement; I wanted my A/C to blow a dreamy 39 F.

 

Welcome to the world of r134a freon. If it was r12 you would be at 36F. There will be another gen of freon coming out maybe 2013 or 2014.

 

I would say both systems are undercharged. Trust me, it's been a balmy 95 - 100 here all summer and the a/c systems I charge usually blow somewhere in the low 40's to upper 30's. The system on your minivan should cycle too, they turn the compressor on and off based on evaporator temp.

 

I don't want to blow up my A/C systems with an overcharge. For the Honda, the Honda Service Manual gives a weird chart for the A/C pressure that's very hard to decipher, so I looked at a Haynes Manual for the A/C pressures, but I'm uncertain of them.

I looked up the pressure for the SXT in the Dodge Service Manual, so I won't overcharge over 35 psi at 90F low side.

I'd rather have a working system than one that's blown up from an overcharge. I can't afford a $1000+ A/C repair from a shop.

 

You'd have to really overcharge a system to do damage. Possible you have air in the system as well, same symptoms. Sometimes it's worth the money to have it done right.