A/C Charge

[alohamonte]

I have not had the a/c servicde since I owned the X, which is 6-7 years now. It blows cold but it's 110 degrees here already so I want to make sure I am getting the most cooling output possible.

So, I have one of those DIY canisters with the built on gauge.

I have never tried to charge my own system before.

My idiotic question is, do I charge the system while the vehicle is running with A/C on Max/High?

 

[1998Exp]

I know that I am not answering your question, but just out of curiosity, what makes you think that the system is low on refrigerant?

I have not had the a/c servicde since I owned the X, which is 6-7 years now. It blows cold but it's 110 degrees here already so I want to make sure I am getting the most cooling output possible.

So, I have one of those DIY canisters with the built on gauge.

I have never tried to charge my own system before.

My idiotic question is, do I charge the system while the vehicle is running with A/C on Max/High?

 

[lobo411]

I have not had the a/c servicde since I owned the X, which is 6-7 years now. It blows cold but it's 110 degrees here already so I want to make sure I am getting the most cooling output possible.

So, I have one of those DIY canisters with the built on gauge.

I have never tried to charge my own system before.

My idiotic question is, do I charge the system while the vehicle is running with A/C on Max/High?

Yes with the A/C running. Doesn't matter if it's on Max/high or not because all that does is close the door that brings in air from outside.

And as 1998exp hints...why do you think it's broken? My experience has always been that A/C is a horrible beast when it breaks, and it's easier to break trying to fix it than anything else on a car. If it ain't broke, don't fix it.

 

[imp]

Repairing A/C by guesswork is as effective as leaving it alone. To properly diagnose inadequate cooling, but not complete loss of cooling, requires the compressor pressures to be viewed on a set of gauges. If expected readings are out of whack, then an approach to repair will be indicated.

High mileage compressors lose efficiency; this shows up especially when they must work hardest, during the hottest weather. A worn-out compressor can no longer meet the pressure requirements for adequate cooling, no matter how much refrigerant is in the system.

If there IS loss of refrigerant, re-charging will bring added cooling. However, if the loss occurs quickly after charging, it's a losing game. imp

 

[alohamonte]

It took all of 5 minutes. With the car at operating temperature, and ac on max, and an ambient temperature of about 106-108, the low side measured a 40 psi. I emptied a can of 134a in there and now it's at 45 psi. It feels much colder now. I would guess 10 degrees colder, almost too cold. I'm pretty happy with this result although I do have a track record of breaking things that work fine in the name of preventative maintenance so I will keep an eye on it. I will be running the ac on max everyday between now and November so if there is a problem it will be apparent sooner or later.

 

[BigCountry1990]

Did you put the liquid portion in or gas? Also, although its much colder this isn't always a good thing. A lot of times if the system is overcharged it blows really cold until it freezes up. Lol also to answer your previous question. Yes a/c max and running is appropriate. With the system on max it keeps the compressor on longer to keep the pressures higher. So it circulates The refridgerant better when you add

 

[my98nnj]

Did you put the liquid portion in or gas? Also, although its much colder this isn't always a good thing. A lot of times if the system is overcharged it blows really cold until it freezes up. Lol also to answer your previous question. Yes a/c max and running is appropriate. With the system on max it keeps the compressor on longer to keep the pressures higher. So it circulates The refridgerant better when you add

Not exactly true.

An overcharged R134 system will stop cooling on excessively hot days if it's over charged. Either the high pressure switch will interrupt the clutch signal or the system pressures will be so high that the low side will lose it's ability to cool from the lack of ability for the refrigerant to expand (pressure drop) through the expansion valve. (low side to high, to much refrigerant)

Max cooling or normal cooling doesn't effect system pressures per say. The compressor cycles to maintain the evaporator temperature. (there's a sensor in there) Max cooling may actually make the system cycle more often, taking the load off the evaporator by recirculating the cabin air instead of pulling in 100 degree outside air. It's more efficient to run the system on Max on really hot days.

Excess refrigerant doesn't make a system cooler, it causes a lack of cooling do to incorrect system pressures. Evaporator temps are maintained by a sensor, it's never going to freeze.