My turn to make an air conditioning issue thread!
 

Well, after 10 years the air conditioning stopped blowing cold. I was excited to refill it with Freon but come to discover that the system is already full @ 40psi.

The center passenger vent will blow cold after 30 min but obviously this is unacceptable.

Do I simply need to drain/refill the Freon, or am I looking at a new compressor??

TIA,
Steve

UGH! This is sure a bad time of year to have an A/C to go out - :(

How did you determine the A/C was full of gas?

When the A/C is turned ON, can you hear/see the A/C clutch engage and disengage?

I'd suggest you take your car into a shop that deals with A/C and have the compressor checked.

!!! STOP IMMEDIATELY !!!

Are YOU trying to fill it with refrigerant? like those over-the-counter bottles from the auto parts store?

!!! STOP IMMEDIATELY !!!

Most of those products have additives/leak stoppers that will contaminate a system and may even clog a modern condenser, some may contain r134a "substitutes" that are not legal for use in on-road A/C equipment. Any not-half-assed AC shop you bring it to once that shit is in will need to evacuate, sequester and destroy contaminated refrigerant with dedicated equiment, flush the system with solvents and replace the condenser if it got clogged by the leak sealers. After all that, only then will they be able to *start* working on your AC issue.

Your car is old and it's still holding pressure, we all know it doesn't have a leak, any respectable AC shop you bring it to will know it doesn't have a leak, they'll recover/vacuum/recharge it no problem, have a glance at it with a UV lamp while the machine is working and you'll get good AC again with no hassle and a comparatively small fee versus fucking around with it yourself and then dealing with having fucked it up.

DO NOT DIY A/C

FYI 40 PSI is almost dead empty. Again, do not DIY A/C, if you didn't know that, you didn't know enough.

Ok well I used a gauge (no r134 can attached) to measure the pressure and did not put any r134 in. 40psi is well into the green on the gauge…what psi should I be at? Should also mention I’m measuring from the low pressure side.

My Camry has a leak, I filled it up to 25psi (I don’t really care for this car so I do things the cheap way with it) and she blows cold.

Be wary of any instrument with a specific zone marked on the dial. AC pressures can fluctuate wildly just based on ambiant conditions and a cheap DIY low pressure gauge is not enough.

This is helpful. I measured it with the cheap gauge at 70F and greater than 40% humidity so 25-38 psi on the low side is the result I’m getting.

I was always told AC doesn’t go bad if the system remains sealed, but since you know your AC, is this true?

Dude, just take it to a shop, I can tell @RZNT4R has shop experience diagnosing car HVAC systems like this and such but you definitely do not.



The gauges you are using are not calibrated for proper pressure measurements, also you can even have leaks out of the schrader cores from mangling them if they are remotely similar to residential or commercial ones. If you wouldn't trust your house hvac to yourself don't do that with your car.



This isn't a Camry and not a one size fits all diagnosis. If you care about the vehicle you really just need take it to a subaru dealer and tell condenser up in a year. Tell them it takes 30 minutes for the ac to blow cold and they will pull it down and diagnose it. That's still cheaper then you shoving the equivalent of a stop leak product into the low or high pressure side and gumming the compressor and condenser up.

SAE A/C fittings have an acceptable loss of 1/4 of an ouce per fitting per year.

Just go to a dealer. They have the proper setup to measure the refridgerant fill level (to grams) and recharge it correctly. Cost will be ~$200 (most of it being the hour of labor and material charge).

Did mine last year with Toyota (~9 year old car) since cooling performance was very poor. They checked for leaks with UV dye same time, which returned no major issues. Car blows nice and cold again.