Aircon pressure, what should it be?
Discussion
Anyone know what pressure the gas in the aircon system should be? It stopped working and I've filled it up to 45psi, the compressor is kicking in but the air coming out the vents doesn't seem to be very cold at all? It was working fine a while ago. I'm sure I read something about 60 psi somewhere?
If the air con isnt working it doesnt necesarily mean that theres a problem with refrigerant charge. As has been said refrigerant is loaded by weight (assuming an empty system that has been purged and vacuumed down to remove all moisture first). Oil quntity needs to be known and checked as well, otherwise possible nasty consequences for the compressor...
Other issues could be around the expansion valve not working properly (either blocked or capillary tube broken etc), heater air blending mechanism not working or water valve stuck open (causing warm air despite working refrigeration).
The easiest way to tell if the refrigerant circuit is working is to feel the suction and discharge hoses with the engine running and the compressor engaged given about 5 minutes for things to settle. The suction hose should be ice cold and with time showing a build up of frost on the outside of the hose; the discharge hose should be HOT (careful). If the hoses are as above then the refrigerant system is fine and the problem lies elsewhere ( likley with the heater box / water valve) If the hoses arent showing the big temperature differential then there is a problem with the refrigeration circuit;
loss of charge,
expansion valve stuck,
compressor U/S (do check that the clutch is actually engaging properly and driving the central spool of the clutch, sorry if that sounds obvious)
etc etc.
Other issues could be around the expansion valve not working properly (either blocked or capillary tube broken etc), heater air blending mechanism not working or water valve stuck open (causing warm air despite working refrigeration).
The easiest way to tell if the refrigerant circuit is working is to feel the suction and discharge hoses with the engine running and the compressor engaged given about 5 minutes for things to settle. The suction hose should be ice cold and with time showing a build up of frost on the outside of the hose; the discharge hose should be HOT (careful). If the hoses are as above then the refrigerant system is fine and the problem lies elsewhere ( likley with the heater box / water valve) If the hoses arent showing the big temperature differential then there is a problem with the refrigeration circuit;
loss of charge,
expansion valve stuck,
compressor U/S (do check that the clutch is actually engaging properly and driving the central spool of the clutch, sorry if that sounds obvious)
etc etc.
Al 450 said:
Anyone know what pressure the gas in the aircon system should be? It stopped working and I've filled it up to 45psi, the compressor is kicking in but the air coming out the vents doesn't seem to be very cold at all? It was working fine a while ago. I'm sure I read something about 60 psi somewhere?
Andy's right, you fill it by weight and from memory I think it's 450 grammes. But if you're really stuck, there's an aircon wizard by the name of John whose' place is called Mirage Air. I've known him for ages and there's nothing in the a/c department that he seems unable to get sorted. Doesn't take liberties with prices either. Sorted my 450 and I don't think the system had been working for ages before I bought it. Problem is he's about 500 yards from the very southern end of the M1 at Staples Corner in North London but if you're really stuck it maye be worth a blast down to see him. His No. is 020 8450 2997. Other than having had great service from John wth a number of different cars, I have no connection with him or commercial reason to promote him here!!! Nick. Gassing Station | Chimaera | Top of Page | What's New | My Stuff