Looking for A/C tips...

Status
Not open for further replies.
If you add refrigerant only - - over and over and over - - eventually, you could run low on the oil charge, also
 
Don't add refrigerant unless you know why you are adding refrigerant, and do so to a pressure/temperature chart with a good high/low manifold kit. And even that is not exactly considered "correct".

Otherwise, you are rolling the dice. Maybe you solve something, maybe you make things worse. Flip a coin.

Things you absolutely can do as an uneducated consumer?

1. Gently clean the condenser with a mild degreaser. I have found Z-clean to work well without messing up aluminum or paint.

2. Check/change cabin filter

3. Check vent temperatures. If you're getting vent temps about 30°F colder than ambient at idle, that's about as good as it gets. Check the vent temps again while misting the condenser with water. If the vent temps get ridiculously cooler, that's an indicator of a condenser cooling problem.

4. Make sure that if you are at idle, and put AC on max cool, or highest setting with recirculation. Leave all doors open. You should not see the compressor cycling. Should be fully engaged. If it's cycling, that could be an indicator of low charge.

If you really want to get "DIY Serious", get a set of manifold gauges, a vent thermometer, and a laser thermometer. That's enough for one of the many Auto AC educated people here to guide you in the right direction.

Again, I'm not suggesting you do this. I'm only telling you what you want if you really want to DIY this. A good AC shop is the better choice if you just want to optimize your system with the least amount of work and hassle.
 
It's too easy to overcharge, you can make matters worse (higher evap temps/warmer) instead of better. That's why the cheap HF gauge set-tell us your numbers, then we'll know whether you're actually low on gas or not.
 
got a aerosol can from HD iand a thermometer from Advance $12 all together.
 
4Runner is below 40, GX 44 prior to condenser cleaning....at least not totally dead....love these old beaters.
 
Originally Posted by dblshock
4Runner is below 40, GX 44 prior to condenser cleaning....at least not totally dead....love these old beaters.

What's the outside temps? Also I see many heater valves that are letting hot water into the dash and heating up the ac.
 
There's not really a 'sealed' A/C system, so at that age, (fourteen years),
if it hasn't been checked for a decade +, refrigerant has escaped out the compressor shaft seal.
Assume about an ounce per year, at most. Pump 6-8 ounces in from one of those cans with the gauge on it & see what it does.
 
A few summers ago, I noticed my A/C wasn't as cold as usual. So, I topped it off using a can of pure Supertech R134a & an AC Pro gauge. I was apprehensive at first but it worked out well. The gauge was a little chintzy but it got the job done. I kept shaking the can while adding refrigerant slowly, stopping every couple of seconds to recheck the pressure. I found 30-32 PSI @about 90 deg was ideal pressure (at least on my Honda). If I would've followed the chart that came with the can, I would've grossly overcharged the system. I only ended up using about half the can. Those several ounces made the A/C ice cold again.
 
Originally Posted by DoubleWasp
And the 4Runner has one. Seen it before on the older ones. Sometimes a source of unintended leaking too.


has one what please.
 
Something critical that few people mention and really can detrimentally affect performance of a car AC system
is a DIRTY EVAPORATOR UNIT which unfortunately is located inside the dashboard.

If this is dirty it decreases airflow and inhibits the cooling process.

The only real solution is to gain access to the evaporator and clean with mild detergent and lots of water...
 
Originally Posted by Chris142
Finally. r134a is weird stuff. Unless its almost empty you can't tell much with pressures. I have had cars come in with only a few ounces in them and the pressures looked normal.


Yeah, like 30psi on the low side not running is something close to nothing.
 
Originally Posted by dblshock
Originally Posted by DoubleWasp
And the 4Runner has one. Seen it before on the older ones. Sometimes a source of unintended leaking too.


has one what please.



A valve to shut off flow of hot coolant to the heater core.
 
Your a/c is working but you think it could be working better. This is a very subjective statement. So many different things can affect the temperature of the air coming from the vents. Is the system in re-circulation mode or fresh air mode? Is the temperature knob turned all the way cool (not blending heat)? What is the ambient temperature (outside)? Are you stopped and idling, or are you cruising on the highway? Have you given the system enough run time to achieve maximum cooling? And as others have said, check the cabin filter, condenser, and overall vehicle condition (cooling system, charging system, accessories, etc). Consider all of these factors before doing any actual work on it.
 
Originally Posted by Chris142
It may only be 3-5 ounces low. Adding a whole 11oz can or even better a 18oz can of ac pro will severely overcharge it.
My Toyota AC system spec for refrigerant charge says 1.4 oz +or- is underfilled.overfilled. I would guess that other makes using r134 are the same.
 
Originally Posted by Yah-Tah-Hey
Originally Posted by Chris142
It may only be 3-5 ounces low. Adding a whole 11oz can or even better a 18oz can of ac pro will severely overcharge it.
My Toyota AC system spec for refrigerant charge says 1.4 oz +or- is underfilled.overfilled. I would guess that other makes using r134 are the same.



Depends on the total charge but the loss of R-134 over time from the system is generally 1.5 oz or less per year...I'd halve that when trying to top off if your AC system isn't cooling well. It's better to have less than more, what you want is for the system to cool well. That's why when you start topping off you put the thermometer in the left center vent and as you gradually add an ounce at a time watch that temperature...(in the sealed car with the AC running) if you can get down to 42-45 F while the compressor is running you're fine. STOP filling at this point. If you reach a certain temp and when you continue to add an ounce at a time and the decrease stops.....STOP adding at this point, it's the best you are going to get.

BOTTOM LINE...BETTER TO NOT ADD ENOUGH THAN TOO MUCH!!!!!!!
 
Last edited:
I agree with the above. Get a temp gauge in the vent and watch the temperatures. They may be in spec anyhow. But if they are not, add slowly and watch if the temperature is dropping, if not there is no need to add more refrigerant.

Also, one can measure the temperature of the AC return line, which should be easier when working alone.
 
Status
Not open for further replies.
Back
Top