I need to charge my system. What are the recomendations? I was thinking of hot shot but I would like to here what others have used and what works the best.

 

If your rig has been converted to R134a already, you can simply go to walmart and pick up a couple cans of R134a and fire it in through the low side port

Start the truck up, turn a/c to max, then fire in more until the bubbles in the sight glass disappear.

Ta da.

 

I don't like those top-up cans. Too much that can go wrong. One customer brought in his Caravan yesterday; "It's not cold, even though I topped it up". He had overcharged it. The high side was pushing 450psi, and the compressor safety switch would trip after a few seconds of compressing.

Our shop charges $40 to inspect the AC system, read the pressures and find any leaks. $120 get's you a complete Evacuate, Vacuum (remove moisture) and recharge. $60 for cans, $120 for the professional to do it.

 

Most will tell you what i done wont work and might not for you.. But i had a bad compressor.. Took one off a motor laying on the ground, put it on, Charged it up with no vacuum pulled.. cools good.. BUT if its not already converted to 134 the adapters that come in the kit are useless.. I went to a John Deere dealership and bought the fittings they use on tractors.. MUCH BETTER MADE.. cost me 20 bucks for the fitting but well worth it.. I done this 2 or 3 years ago.. still cools good.. 39 degrees at the vents.. Your results may vary..

 

If your going to charge your AC yourself you should look at the identification and or retrofit stickers, find out the quantity, and then add refridgerant very very conservatively. what ever you do DO NOT buy the refridgerant that comes with sealer in it, many of the cans you get at wallmart, shucks, autozone, et. use sealer. If you put that sealer in your system you basicaly condem it from ever being worked on again because that sealant will destroy a recovery machine at a shop, and needs to be extracted with a special machine into a different bottle. most shops wont even touch it.

 

It's normal for 134A to show bubbles in the sight glass. If you charge until the bubbles disappear, you'll be way overcharged. You really need gauges to do this right.

I found on mine that a low side pressure of 25psi low-side works great with 134A on a converted unit. (90 degree outside temperature, radiator still cool.)