how accurate is part store a/c pressure gauge

[julio]

on my 07 the a/c is blowing cool but not cold. i think its right on the edge of needing just a little freon cuz going down the road it sometimes does blow cold air. my question is how accurate are the a/c pressure gauges that are sold in the parts store? thanks in advance

 

[Sepiroth]

Not very.

 

[Landshark]

I have the same issue with mine. I bought a can to try it out. When I hooked it up it was at the top of the "serviced" line on the verge of going into the overserviced area. I just left it alone.

 

[julio]

I have the same issue with mine. I bought a can to try it out. When I hooked it up it was at the top of the "serviced" line on the verge of going into the overserviced area. I just left it alone.

so did you have it serviced? is it blowing cold air now?

 

[julio]

well since i had one of those cheapy gauges laying around but had never used it i decided to try it. the gauge i have shows green, yellow and red. it was half way in the yellow so i went and bought a can of freon and put it in. i checked it after and now its 3/4's of the way in the yellow. a/c is now blowing cold. guess i got lucky but ill keep my fingers crossed.

 

[73shark]

If a three year old truck needs freon, then you probably have a leak if the system has never been opened.

 

[julio]

i dont think it so much the age but the mileage. i have 49k miles on it and a/c runs 90% of the time down here in hot humid texas. i can live with adding freon every 2 yrs.

 

[73shark]

The A/C system is sealed. Freon is not a consumable.

That being said, there will be a minor loss over time due to leakage at the seal on the compressor shaft and migration thru the hoses but that is minor and shouldn't lead to needing a recharge after a few years.

 

[hapyspaz]

Most common leak is at the schraeder valves, usually due to the caps being overtightened. Most people pull the caps off to do it themselves, small debris gets into the cap, cap gets overtightened, and you create your own leak. Also, the valves give out over time, small rubber o-rings dont last forever.

 

[Landshark]

Was driving down the road today with the A/C blowing and it started to feel warm. My wife said she was freezing to death. Checked her vents and they were still blowing cold. Both drivers vents were not as cold. Checked the settings and the passenger selector was turned off so both sides should have been the same. Is the A/C controller going out or something else?