Air Con recharge - port identification

[BigCatXJS]

Evening All,

I'm looking to add some lub/sealant gass to my air con system as I have a very small leak somewhere that causes the system to discharge over a period of 6 to 9 months. The last time it was checked (6 months ago) it was holding vacuum okay. The compressor is still kicking in but I'm getting a lot of hissing and wheezing noises (the car not me!!) when the air con system is running suggesting that the gas is getting low again. It did this last year before I lost the cold air.

Could someone let me know which (out of locations 1 and 2) is the air con low side port?

Its a 1994 4.0 Sovereign with a R134 system.

Thanks, Rich

[davidr]

The 2 ports should be different sizes so they can't be mixed up. If you're using a top up kit then it should only fit on one port.
This should be the low pressure port which is the one leading to the compressor.

[BigCatXJS]

Thanks David - I'll check this at the weekend when the XJ40 is back at home (currently pressed into service by my wife for most of this week).