What is the difference between getting a recharge at a shop and adding R134 from autozone? I have worked with large air conditioners on a submarine and everytime we "recharge" them it is just adding R114(in this case). Unless if i just add 134 i wont be able to purge non condensable gases?

 

at Nissan they create alot of vaccuum in the system before they put the charge in there.

If you just recharge it your yourself, it "might not" get as cold as it should. But for ~$12 its probably worth a shot.

 

Yes, this very true. It took the shop that did mine an hour to suck all out and put back in for we couldn't get the pressure to specs. But it all worked out in the long run.

 

If you have to recharge it, it has a leak, if it has a leak you should repair it, if you repair it, it should be flushed and if its apart and going back together, it has to be Vacuumed to remove moisture, then charged.

Vacuum and test for leaks after 5 minutes, If no leaks, then vacuum for 30-60 and charge.

If there is a leak, did you loose oil???? That has to be determained.

If its been leaking for awhile or if its empty, you have to replace the Accumulator.

 

I think the OP just installed a TN kit, so he has to recharge his AC. I havent tried the autozone kits. We use a special AC refill tool, but I dont see why you couldnt try the AutoZone kits.

 

In all due respect, if he opened the sysyem and replaced the Hose with the TN Hose, He HAS to vacuum the sysyem.

If he, on the off chance, had the Vacuum pump, Yes--the Auto Zone Kit would be fine---of course after putting in the 2 cans or whatever it takes, its anyones quess what Hi/Lo readings are, and that, like a vacuum gage or a A/F gage, tells you whats happinin.

I am not trying to complicate the issue, just mentioning basics for COOOOOOLD air

 

BTW ---The Aloha State is humid and thats the purpose of vacuuming the system ---to remove ALL moisture

 

Not trying to complicate it. Since we are not a repair facility, we do not have the $10,000 AC recovery and recharge systems. We do it the old fashioned way. It does work...we've done it dozens of time.

 

LOL Well the price has gone down and neither do I, My freon joins the 99.999 % of Cloro-Floro-Carbons that are released by smimming pools every day. And I dont need a tree hugger rant ---I love trees too !!!

A nice vacuum pump is 400.00 and Im sure Sharif knows that moisture in a vacuum boils and in this case, boils and joins the CFCs, Silicons,Acids, and Cow Farts ( Methane Gas/CFCs ) in the atmosphere. Moisture and freon dont mix and efficiency is hindered.

Im not saying buy a 400.00 pump, Im not saying, turn your pool into a vegitable garden, Im not saying, shoot your cows. Im just saying if you want the best of the best, vacuum the damn thing.

 

just go to an A/C shop.....it should take less than 1 hour and shouldn't be more than $75.....and you know it's done the right way.

for one thing, they pull vacuum on the system which will check for leaks in the system....definately a good idea since you changed one of the lines!

 

The moisture reacts with the R134a and the lube oil when heated in compressor to create acids which eat the evaporator from the inside out.

What causes all the age related leaks in evaps.

The silica gel in dryer gets mushy and breaks down when exposed to too much moisture.

Usually the second owner is stuck with the bill from abuse buyers not maintaining AC system.

My 1990 Q has a 312k 17 year old evap, thanks to periodic vacuuming down and recharging and replacing the 8 oz of lube oil every 3-4 years. Still uses R12 and never any substainal leaks [orings +hose permeability].

Depends on how long you want to keep vehicle how much you spend on preventative maintenance!

 

The silicon Gel or Dessicant in your Accumulator/Dryer is designed to remove tiny amounts of moisture in the system and when exposed to the atmoshere for a relatively short period of time ( depending on the humidity ) sucks up moisture like a sponge, thereby ruining it by plugging it with spent dessicant.

Situations like that are when the gages come in to play, because pressure differential tells you that.

Nissan uses an Expansion Valve to meter the freon into the Condenser where as GMs use an Orifice Tube. Either way, they are ruined also. The OT because it gets plugged and the EV because it seizes up.

Either way do as you please---Flush it out with water and fill it with Propane if you want. ( Knew a guy that did that )

 

Get a new drrier from nissan and replace the old one. Then just dump some 134 into the system to pressureize it. Once pressureized look for leaks everywhere you made a break in the system. Once youre sure there are no leaks connect your charging hose to the low pressure side and leave the can in the upright position so only gas will be drawn into the system.
Start the car and turn on the a/c, the charging can should start to get cold as the 134 is pulled into the system. Now you only want to add some 134 not a complete charge. The air that is in the system will collect on the high pressure side, if you had a set of gages on the high side you'd see that the pressure is too high. Now turn off the A/C and drive around a little to cool the condenser, you could also just let it sit an cool off. Now vent off pressure from the high pressure side. What you're doing is venting off non-condensible gas (air) from the system. You will need to do this several time to get a complete charge and all air vented. 134A is an HFC and does not harm the atmosphere that we know. This is not the proper way to charge an auto a/c but it works, it's called a sweep charge, the old school way we did things. I would recomend having it properly evacuated as you do need to ensure all the moisture is removed because as stated before it will cause extensive problems in the future.

 

Interesting