rnln

I bought some 134a cans to recharge my AC again today. I have been using the cheap nozzle and single gauge which come with the bigger can to recharge and always “feel” it is not that accurate, and somehow I also feel scared holding the can on my hand. I have read many people warned that there is a chance the can might explode, etc.

What I did was hooking it to the lower valve and lowed the lid, then pulled the trigger. It took me well over an hour to finish two 12oz cans. When I am done, taking of the hose, I still hearing some hissing noise and air was comming out of the cans (no liquid). Most of the time, the gauge showed way below 25 psi. Once I turn off the engine and retart again, the gauge showed a little higher (close to 25 psi). I doubted the gauge is correct, so I hook it up to my Lexus which has perfect AC, it showed 65 psi. During the procedure, sometime the trigger got stuck. I had to take the nozzle off the car and spray it out, then try again and it works.

Right now, if I hook it up to the lower valve, sometimes it show 24 psi, most of the time it show 1/2 way of 25 psi.

My question is if the “A/C MANIFOLD GAUGE SET” with 2 gauges and a bunch of hoses at Harbor Freight is any better? For $40, what kind of advantage(s) will I get?
Can someone help me to point it out?
Also, is it easy to use?

3.2SLANTNOSE

It would be better to have any brand, of a working manifold gauge set, over what you are trying to use successfully. That way could see and watch both the low(blue/cold) side and the high pressure(red/hot) sides of your A/C system. The amount of time you said it took to discharge the amount refrigerant that you were install is an extremely long amount of time. I have never seen any freon or refrigerant can explode from being connected to a correctly working, low side hook-up. I have not seen it done on the high side either, but I suppose that it could be possible, but you would have to really try to have the can connected to the wrong port on a 134A system, being the fitting are of different size, but that does not mean that a "converted R12 system, could not have the wrong fittings on the wrong Schrader valves. It is possible for someone to have reversed them. Some car manufacturers had a different size port opening for the high and low sides, some didn't. But... all of the retro and factory 134A port connectors are of different sizes, basically a "polarized" system, that way they will only fit one way, the correct way. The only problem you might have with this, would be on a converted R12 to 134A system, that required someone to decide what port opening fitting to use on whatever side they chose. You never can tell what some people might do.
The reason that you get a little blow off even when the can appears to be empty, is because although the can is empty of liquid product, there is still residual pressure, from the equalization of the pressures in the low side of the A/C system and the connected charging can. If the can is actually empty you will get a small blow off when changing out cans even with a manifold gauge set. If you get a blast of liquid, it is because the can was not yet depleted and emptied.
I personally do not like, nor do I use, any of the "plastic disposable" type of charging equipment. Get a set of gauges from your favorite source, and a 30lb jug of 134A, from Sam's if you are going to have to keep topping off your converted systems, it will save you money to do so. Both the gauge set, and a 30lb jug of 134A can be had for less than a $100 dollar bill. I don't know how long, that 134A will be "cheap" I know the super high prices have gone back down now, from reaching $300.00 +, because the big-*** dam in China got finished buying the worlds market of 134A to chill all of that concrete they poured for the 3 Gorges Dam. Good luck!! Tony.

rnln

I didn't see the gauge set at Samsclub but saw the 30lb tank. This tank might last me 10+ year . Do you, or anyone else, know if the tank properly sealed tight when closed off or it will slowly leak after time?
Thanks.