Leaking AC

So I have a problem: my AC leaks, and it's September (hot as fuck) in California.

It's a pretty fast leak usually needing a revisit from a refridgerant can once a week or so, it appears to have gotten worse. I've run through 1 can in ~1 month or or so now.

Truck: 2012, ~75,000mi, no professional A/C service to date.

Backstory: I was on a fairly hot trail with a large group and, somehow, the AC got set to "Max AC" maybe an hour or two into the slow trail with many hill climbs the A/C suddenly started blowing hot humid air at us. We turned it off and went windows down for the rest of the day.

Following day the A/C was fine. For a few months after the A/C started to get weaker it seemed (blurry past to be honest) and continued until just before the 15th of August or so it just went completely out. A 30mi drive that takes well over an hour would blow hot air the whole time.

To date now, I've used a can of refridgerant, and she's blowing hot again. When the A/C is turned on you hear a "hissing" noise through the blower that goes away if the A/C button is pressed.

Does anyone have ANY advice before I limp into a dealer on Friday 9/16 and get raped?

 

Nothing more than to check for leaks. At least three ways to do so.

easiest way is to visit harbor freight, drop $75 bucks and buy a refrigerant leak detector.

Next easiest is to go to lowes or whatever and buy a spray bottle of gas leak detector. It is just a good soapy mix that will produce bubbles if it is sprayed on a leak. You will have to spray everything from compressor to firewall. If you find nothing, it will most likely be an evap core problem since you say it is leaking quickly.

Final choice is to buy a can of R134a with UV dye in it. Let it leak for a day and then take a black (UV) light and shine it anywhere the refrigerant lines go. If you see a green glow, you have a leak at that point.

Of course, finding the leak is often the easiest part of the process...

 

That's what I'm reading as well. I'm not sure the fill hose I have works for the cans I saw that had dye in them, I tried one more that says it contains a sealeant.... we'll see what happens. It was fully empty again

I think I'll have to stick to my Friday plan to take it to Toyota and just have them shuttle me to my office. So painful...

 

Do NOT use a "sealant". That only invites further trouble, as it can "seal" the Tx valve opening, or the compressor, etc. Pressures are too high for this crap do do anything useful, other than to make the seller some money. I've never seen cans of R134a, with or without dye, that were threaded differently. There is an industry standard for this that should never be violated. R12 (pre 1995 or so) is a different animal with different connectors.

Letting the dealer take a look is a good idea if you are not experienced in refrigerant systems. But it can get expensive

 

running on max a/c shouldnt do any damage or cause problems...

 

I just remember crawling for a fairly slow pace for a good while (mild hill climbing here or there, no rocks though) and boom suddenly the A/C starts blowing hot and humid air. It wouldn't cool down after that either.

Since that day the A/C was always a little "funny." Long to cool off, starting to blow warmer and warmer. One day (week ) in August it just suddenly went dead. Hot air.

 

It is POSSIBLE that you blew out a hose (or even the evap core), or that the pressure blew off the pressure relief on the compressor, loosing a significant part of your R134a charge. If you move slowly, the A/C works much less efficiently since there is no air to speak of going through the condenser/radiator. Less air flow means less heat removal, which makes it harder to condense the R134a gas back to a liquid, and pressures rise inside the A/C cooling circuit. R134a already runs at high pressures. If you cover the condenser with a piece of paper, I have no idea how high the pressure will go since the compressor adds to the heat / pressure level and the condenser is ineffective at removing the heat, leaving the pressure elevated.

Whether you use recirc or fresh air would not make any different to speak of, although fresh air would probably do a bit worse since that is introducing hotter air (than recirculated air) over the evap core which will again raise the A/C refrigerant circuit temp.

 

That's kind of what I figured. I'm hoping it's as simple as a hose but nothing appears to be out of place... I just haven't had a good day to review it with the engine not fuckhot after a 40 mile freeway drive. Today I will have a chance to look at it later as I'm likely not driving anywhere.

Is the pressure relief you speak of a removable component or like a "blow off valve" that opens over a certain pressure? Any "weak points" I should check first?

 

Subbed My AC has been like this since I got my truck. It's always "worked", but doesn't blow as cold as it should and a couple times, it started blowing hot air for a minute or two before going back to cold. It also hisses and wheezes like it's got emphysema.

 

Sounds a lot like mine!

Find a can of the refridgerant with dye I haven't yet and the last can I put in didn't have it.

Don't forget to turn the cans back in for the $10 refund -_-

 

Honestly I haven't been too concerned about it, it's on my 'to do' list for my truck but it's toward the bottom....it's a long list, lol. I rarely use my AC, I'm indoors during the hottest parts of the day at work, and when I'm out wheeling (as you know) I don't use it so my engine stays cool. Also I've noticed if the AC is on, it really hinders my truck's performance (acceleration, gas mileage, etc.).

 

Yeah going into the winter months soon here has me thinking if they're gonna ask an arm and a leg for A/C repairs...... it can wait.

 

Actually it is probably the exact opposite. Not a lot of demand for A/C work during the winter so you often see good deals advertised...

 

No I mean if they want to replace a bunch of shit and play the guessing-game of repairs I can wait a few months before I dig into it.

 

So... Update.

The hiss is gone when the AC is on. I checked it with the hose/gauge I've been using and it showed the same pressure that it had when I last gave it a rrecharge... It's lowish but hasn't moved.

But things have changed. Only the drivers side blows cold now. Passenger side is warm to ambient air temp.

I'm taking it to Toyota tomorrow morning... I'll bring extra lube.

 

Dealer found the leak in a hose. Holding the truck over night.

I didn't bring enough lube for this.