AirCon Advice

[BrettV8]

Hi All, looking for some advice please. I have a 2007 XC90 V8 that I bought in October. I’ve just got round to trying to get the aircon going so added some gas to the low side. When connecting it initially showed no pressure. I filled to about 20psi and what was left in the bottle was used up. At that point the air con kicked in and was cold but only really cold on all the right side air vents. I did notice that the radiator fan sped up when the gas was added but not to full speed. It’s held the 20psi for about a week but the fan has stayed on regardless of if air con is on. I have now added some more gas to take it to 35psi and the fan has now gone to full speed and will just stay on whether the air con is on or off at that speed. The engine temp speed is not even up to running temp. I’ve added 134a and it’s def 35 psi as I’ve checked on another older hose and gauge. I would be so grateful for some advice as running the fan at this speed will likely kill it in next to no time.

[Kev0607]

Are you using a proper machine to add refrigerant, or the little cans you buy?

The cans are useless.

[Clan]

Originally Posted by BrettV8

Hi All, looking for some advice please. I have a 2007 XC90 V8 that I bought in October. I’ve just got round to trying to get the aircon going so added some gas to the low side. When connecting it initially showed no pressure. I filled to about 20psi and what was left in the bottle was used up. At that point the air con kicked in and was cold but only really cold on all the right side air vents. I did notice that the radiator fan sped up when the gas was added but not to full speed. It’s held the 20psi for about a week but the fan has stayed on regardless of if air con is on. I have now added some more gas to take it to 35psi and the fan has now gone to full speed and will just stay on whether the air con is on or off at that speed. The engine temp speed is not even up to running temp. I’ve added 134a and it’s def 35 psi as I’ve checked on another older hose and gauge. I would be so grateful for some advice as running the fan at this speed will likely kill it in next to no time.

The system must have a certain weight of liquid gas in it, a label somewhere will state what that should be, The pressure gives no indication at all of the amount of Liquid gas in there.
Get the system checked and serviced by a certified Motor vehicle AC engineer, and save yourself some money.. It is illegal to tamper with Vehicle AC systems. max fine for letting gas out into the atmosphere is £40,000.

[Tannaton]

Originally Posted by Clan

The system must have a certain weight of liquid gas in it, a label somewhere will state what that should be, The pressure gives no indication at all of the amount of Liquid gas in there.
Get the system checked and serviced by a certified Motor vehicle AC engineer, and save yourself some money.. It is illegal to tamper with Vehicle AC systems. max fine for letting gas out into the atmosphere is £40,000.

As the gas turns to liquid at a certain pressure, you find that as you pressurise the system when it starts to liquify the pressure no longer goes up the more you add. Hence the only way to know if the correct amount of refrigerant and lubricant is present is to drain, vacuum and refill....

[BrettV8]

Thanks that does make sense re the pressure. Everything seems to be working as it should with the exception of a likely blend door issue not balancing the cold air between left and right side of the car. It was worth the trial load with a can to know it can hold pressure, the pump and solenoid work and the ccm can see/control the temps. It wasn’t worth a vacuum and fill if I was going to need to replace any of the system parts. Grateful for the replies.

[Tannaton]

Originally Posted by BrettV8

Thanks that does make sense re the pressure. Everything seems to be working as it should with the exception of a likely blend door issue not balancing the cold air between left and right side of the car. It was worth the trial load with a can to know it can hold pressure, the pump and solenoid work and the ccm can see/control the temps. It wasn’t worth a vacuum and fill if I was going to need to replace any of the system parts. Grateful for the replies.

Many of the high street chains that have the machinery do not charge the full amount, or anything at all (Kwik Fit), if the system fails the leak test and they can't fill it.

I took a 20 year old Discovery into Kwik Fit a few years ago for a a/c recharge, it passed the leak test, they filled it, about a minute after starting the engine and turning the a/c on the condenser failed catastrophically - no charge to me.