Recharged my A/C today

[My98RT10]

Went to the shop today to get my A/C checked. Have the car for 2 years now ('98 RT/10) and so far A/C was always working ok. Don't use it that much though as it doesn't get really hot so often in my area. I went there mainly because I was curious as to how much refrigerant might have get lost over the years (don't know if it ever had been recharged...).

Here's how it worked (for those who are interested):

First step after connecting the aircon device (Waeco ASC1000) was evacuating the remaining refrigerant and oil from the System.
Second step was pulling a vacuum (that took about 20 minutes).
Third step was a leak test where the device measured for 3 minutes if the vacuum remained stable.
Fourth step was refilling the system: first oil then the UV trace stuff and finally the refrigerant (that took just 2 minutes).

Interestingly enough, my system had only 75 grams of refrigerant in it where the factory charge was 822 grams! So quite a bit got lost over the years. Luckily the leak test was passed ok so I hope that everything will be ok for the next 2 years.

The guy also tested the Performance of the System. The lowest temperature measured at the dash vents was 3.2° C. I had never measured it before so I don't have a reference but I was surprised that it got that low. At this point the compressor disengages to avoid freezing the system (that's what the guy said).

Last but not least, the complete check was 60 € (approx. 80 $US).

[TitleMine]

I just had this done too. Worked great.

[Bugman Jeff]

The guy also tested the Performance of the System. The lowest temperature measured at the dash vents was 3.2° C. I had never measured it before so I don't have a reference but I was surprised that it got that low. At this point the compressor disengages to avoid freezing the system (that's what the guy said).

This is an important check to do, especially if you're charging or topping off your own AC. If the system drops below freezing(0C/32F), ice can build up on the evaporator. At best, ice build up will block the airflow and it'll stop blowing cold air. At worst, enough ice can build up to crush the evaporator(though that's pretty rare and takes a really humid day with a very overcharged system). It's important to know because not all Vipers shut off when they get to freezing. When I charged my AC this year, I wasn't paying enough attention and I overcharged it a bit. It was blowing 28°F/-2.2°C out the dash vents so I had to let some freon back out(gauges were both still within the specs). Typically, I charge until I get a steady 40°F/4.4°C from the dash vents and call it good. I've never had gauge pressures out of spec when charging using the vent temp method, though it does take longer because you've got to let the system settle it's temperature after adding a bit of freon.

[Cap'n Hook]

If it were me, I'd never need A/C if I had an RT, the top would be off all the time! Cheers!

[City]

If it were me, I'd never need A/C if I had an RT, the top would be off all the time! Cheers!

At some point, I recall an A/C specialist saying that the "optimal" dash vent temp was 50 degrees F.
Regardless, although I agree completely with Mr. Hook with regard to the open roof driving, there's nothing better than a cool breeze when it's 90 degrees out and you're slowed in traffic. Roadster/Convert owners can attest to the benefit of A/C even with the top off or down.

[C.J]

The Dodge factory service manual has a chart that shows what the temp should be coming out of the dash based on the ambient air temp and the associated high and low pressure readings. IIRC, it was between 50-60F.

[My98RT10]

..., there's nothing better than a cool breeze when it's 90 degrees out and you're slowed in traffic. Roadster/Convert owners can attest to the benefit of A/C even with the top off or down.

Fully agree!!

[Coloviper]

Wasn't there a simple o-ring fix for most Viper A/C systems that lose pressure mysteriously? I recall something from years ago. Mine, I charge myself in the Spring and is hood all year but after sitting in the winter, she be low in need if charge again each Spring. I have been thinking o-rings but the DIY article is behind membership of old site for reference. Anyone have experience with this for all us folks over here? Might help OP as well.

[C.J]

There are two o-rings where the lines connect to the compressor, and those tend to dry out and start to leak. Pretty easy to reach and replace with the compressor on the car. There were o-rings where the dual-pressure cutoff switch bolts up to the accumulator. Tom Sessions mentioned that there are o-rings where the lines connect to the evaporator coil, but I think you have to remove the front fascia to service those. I've replaced all o-rings except the two up front at the evap coil, and my system lost pressure over the winter. Surprised me, as it held a vacuum for 24 hours before I charged it up. Remember to evacuate the refrigerant before changing out the rings, but otherwise it is pretty simple to do.

[Coloviper]

Thanks CJ! Wasn't there also something about the type of O-Ring to use, if I recall. I thought it had to be the green ones or something like that. Kinda wish someone just had the DIY article over here. My leak is not too bad either as the charge lasts all year long but every Spring I have to charge it.

[C.J]

The green rings are commonly used, although the rings that came with the new Denso compressor were black.