A/C cold while driving, warm while idling

for comparison sake; when moving 65 mph down the highway; you've got a 65 mph wind-tunnel moving through your AC condenser. Your fans is moving considerably less air - ergo warmer air coming out of your vents.

 

Yes with age the Schrader valve inserts can definitely go bad and you need to use inserts that are rated for refrigerant duty tire valves are a no-no

 

Thanks for the update. I have an AC system on a fairly new Toyota thats not blowing cold air. Will have to look into this.

 

These are small volume critically charged systems.

Two cautions-
Don’t overcharge a variable speed high voltage compressor. Recover, evacuate and weigh in new refrigerant.

Second don’t use cans with sealers or normal refrigeration oil mixed in. Only pure refrigerant and if needed, specific oil made for high voltage windings.

Bonus - systems don’t use up refrigerant. When recovering weigh the result. Less than factory means a leak.

 

Make sure your fans work Make sure you have ample cooling through the condenser which is in front of the radiator so poor cooling of the condenser will probably equal poor cooling of the radiator somewhat also debris dirt and stuff can do it once that's clean and everything is noted to pull air then check your free on level but down and dirty way to do it is to have somebody turn on the air while you're standing right next to the sight glass looking down at the sight glass you see bubbles and moving and that's about it the system is lacking in refrigerant. You can hook a can tap to a can of straight 134a undo the cap in between the engine and transmission mark low or l attach said Freon hose and gas up slowly hopefully your low side connection has a gauge on the can tap You're looking for right around 38 to 40 PSI somewhere in there your bubble should have disappeared before you got there and you should have turned the can tap valve closed just leave it laying on a hose or something while you watch the sight glass viewing the hose that the refrigerant is being pumped into It should now be quite cold like you don't want to keep holding it cold the sight glass should essentially be clear and you should be looking right at 40 PSI on that low gauge now you can disconnect and go on about your business. Or you could have stopped when you hook the gauge up and noticed whatever and then taking it over to the shop so they can suck it down charge it up by weight and charge you 200 plus dollars It's up to you I generally don't opt for the $200 or better. My AC has been running well most of my life and everything I own.

 

How do you know you have a leak per se A refrigerant air conditioning system charged up with say R410A R134A refrigerant gases they're allowed to leak X amount of gas per year over the lifetime of the system so when people say that air conditioning systems don't use gas or freon of course they do there's no way you could have 100% leak free system forever engineered into that system is the allowance of X amount of leakage whatever that is that's for you and the company and paperwork nightmare to deal with not me. So over a 10-year period of owning an air conditioner sitting in a vehicle that moves and drives down the road has vibrating hoses o-rings and fittings that have to be tightened and clamped together. You're saying there's no allowable leakage factor and that type of system yeah okay we'll leave it at that. Now I'm not talking and open hole in a hose a broken o-ring so on and so forth I mean everything as new there is an allowable standard for what is allowed to come out of that system over it given amount of time. Point blank. If you have more leakage than that and in fact think you have failing o-rings. Permeable hoses whatever may be going on You have to get that straightened out obviously first That's what a vacuum test engages tell you when you've done that work and you hold vacuum for X amount of time so on and so forth. But if you're just saying your air conditioner is a little low after 7 years on the road. I would say to myself and to you top it off look at your sight glass while doing so get the thing making cold pretty much like it was and keep an eye on it maybe if you have reason to believe that you have more of a leak than you might think But being down a little after 7 years 5 years somewhere in there is not abnormal at all and would not give me any calls for alarm thinking that I have some big leak If I'm down enough and I'm pretty much like essentially empty and it was a new to me vehicle or something I might crack the hose fittings and apply the latest o-rings out of the latest materials for the application possibly a receiver dryer if it's a replaceable type like in Corollas and vans and what have you vacuum it down gas it up and let it rip. No I do not advocate leaks so I won't gas up to a leak I fix the leak first then gas up but you probably don't have a leak.