warbirds76

not much of mechanic, but trying to recharge my AC before the summer. Went to auto zone and got the freon recharge canister. When I hook it up to the input valve, the gauge reads full pressure. AC blows hot and all other parts of the unit are running as best as I can tell. Should I still add the freon or will I overpressure and blow something out? trying to avoid $100 mechanic cost for recharging, but don't want to blow up my AC unit. Thanks

tech2

is the a/c compressor clutch engaging when the engine is running and the a/c is on.

warbirds76

yes...it kicks on like it is supposed to...I wouldn't think I would need to bleed anything if freon is escaping. The gauge on the freon canister shows full pressure so I am kind of at a loss. I took it to the shop last year and it just needed recharging. I am wanting to sell it at the end of the year and don't want to pay a grand in AC replacement. I already have to have the lower main seal replaced.

tech2

with the a/c running for at least 2minutes; locate the a/c service ports near the accumulator. there is a orfice tube between the ports. this is the dividing point of the high and low side. touch the lines... one side (the high side) should be hot. the low side should be cold.

tech2

if worked ok after the shop charged it i'm guessing? charging using the method you have used is not accurate.
Usually, if the system is undercharged the compressor will short cycle...cycle on and off rapidly.


Now that you added that cocktail refriderant... the shop can't charge it without contaminating their a.c machine

V12TT

Summer is coming and I haven't looked at the AC for many years so it's time. I want to do the right way with evacuation then recharge.
I looked up the capacity for ESV and it calls for 11oz PAG and 48oz R134a. It looks straight forward to add 4 cans of 12oz R134a but how much PAG 46 oil do I need to add or any at all?

tech2

were any parts replaced? Was the system leaking?
esv is what? What vehicle do you have?
3lb refriderant seems like a lot and 11oz of pag seems like a lot

V12TT

Escalade ESV. No parts were replaced. Do I need to add PAG 46 for emptying and replacing?

V12TT

On the leaking question, how can you tell how much you lost unless you evacuate the whole system and measure?
I placed a thermometer on one of the vent and get 44F with fan on minimum and setting on 60F.
Does that answered the question on leaking?

tech2

the proper way to charge the system is to recover the refrigerant. record the amount of pag oil that came out during recovery (the ac machine has a oil recovery bottle). If the system is inoperative or has poor system performance there may be a leak. to accurately charge the system, vacuum the system for at least 20minutes, add the amount of pag that came out during recovery, and charge the system to the amount specified on the ac label located in the engine compartment. if you have no idea of the amount of oil lost and the system still has some charge...add 0.5oz

no idea the year but for reference a 2007 esv front and rear system takes 2.5lbs of r134a