Automotive Air Conditioning Information Forum

Looking for advice regarding my 2007 Toyota Auris. I had the a/c recharged last year and the system was working great until this week, it's now just blowing warm air. Thought the problem could be a leak in the system and the pressure has been lost, checked the pressure and it is fine. Changed the cabin filter which made no difference.
What other checks could I do?

I assume you checked pressures with that single gauge deal that comes with certain kinds of AC Pro recharge cans.
If so, please know that
1) Never use any AC Pro or similar product if it has any sealer. You will destroy your system with sealer no matter what the can says. And that single gauge is highly inaccurate
2) you need a pro-style manifold gauge set to check pressures. It has hi and low pressure readings
3. We do not use a manifold gauge set to determine how much refrigerant is in a system. It doesn't work that way.
Strongly suspect you have a leak. An electronic sniffer is the best way to find them. The dye method is second best.
Perhaps the best course of action right now is to have a pro shop that is MACS certified recover, evacuate, and recharge the system and have them install a can of dye and then keep your eye out for leaks, and then if you are capable, repair them, or let the shop repair them

Do you live in a country that uses ice melting chemicals on the roads in winter? If so, look for signs of corrosion and evidence of oil leakage on any metal refrigerant lines routed down low in the engine bay. If you don't find anything there, the compressor shaft seal might be faulty. Visually check the area between the compressor case and clutch for traces of oil.

Other than those possibilities, the leak(s) could be at an o-ring joint, the condenser, the evaporator, the receiver/dryer, a hose or another metal line, and/or at a pressure switch. As already suggested, you'll need to go over the entire system with an electronic refrigerant detector to find them once the system has been recharged and UV dye added. At that point, visually check the condensate coming from the evaporator (just behind the engine and under right side of the car) for the presence of the UV dye, which would indicate a refrigerant leak in the evaporator or its connections.

I carried out an inspection for any leaks, nothing found. One thing I did notice is that the high pressure metal pipe is very cold. I am now in the process of booking it in to the air con shop.

The high-pressure side of the system should be hot. Are you sure you were looking at the HP side, the thinner of the metal lines and hoses?

yes, definitely the thinner metal pipe line is cold the larger diameter low pressure line is at ambient temperature. Perhaps this is happening because of the problem with the a/c?

Obviously, the compressor must be running when you do the touch-test. Is it?

yes, compressor is running.

I still suspect that the system is low on refrigerant due to a slow leak someplace, although it hasn't leaked out enough yet to prevent the compressor from running.

By "blowing warm air," do you mean heated air or ambient air?

The problem was because the system was low in pressure. Took it to a A/C workshop who recharged the system an put some kind of leak lubricant in the system. Four months later I have a squeaking noise somewhere around the front pulley area, more than likely a noisy belt tensioner or idler bearing, noise comes an goes and seems a bit worse when the engine is hot. I hope it's not the a/c pump, what do you guys think?
https://www.youtube.com/watch?v=9X2L8wezVfw