Quick air conditioning question

[Doc Voliday]

A/C stopped working. I hooked a gauge up to it to see if I needed to recharge the system and it acted a little funky to me. I'm no A/C expert though.

When the compressor is NOT running the pressure on the gauge builds up to the red within a few seconds. Then when the compressor kicks in the gauge drops all the way down. I have the A/C on and fans on full blast. It's about 80 in sunny Charleston, SC right now.

Also, it felt like the hose on the gauge was swelling up a bit when the pressure was building. Seemed odd to me.

 

[rymax101]

Be careful when working with refrigerants.

The low side should read around 40psi at 80*F. This relative though cause humidity and airflow over the condenser affect this. I believe our cars cycle(disengages the clutch) when the low side psi gets to 15-18psi.

Too much refrigerant will cause high side reading to be high. At proper charge the high side should be around 200psi at 80* outside.

When off the system equalizes causing the system go around 90psi all the way around.

 

[Wings65288]

Mine quit working or wasn't working when i bought it i should say. I'm just gonna remove the A/C system and cut about 35 pounds up front


Sent from my iPhone using svtperformance.com

 

[keith89]

Mine quit working or wasn't working when i bought it i should say. I'm just gonna remove the A/C system and cut about 35 pounds up front


Sent from my iPhone using svtperformance.com

Not sure how that helps the OP.

OP, it sounds like you are low on refrigerant and may have a leak. The low side will read high with the compressor off but will drop when the compressor turns on. Can you tell us what your low and high side pressures are with the compressor running?

 

[Wings65288]

Not sure how that helps the OP.

Yeah you're right. I was going to have mine repaired and then after thinking about it for a while I'm just gonna remove it for the weight savings. My windows are mostly down anyway. Just throwing an alternative out there for him.


Sent from my iPhone using the svtperformance.com mobile app

 

[Doc Voliday]

Not sure how that helps the OP.

OP, it sounds like you are low on refrigerant and may have a leak. The low side will read high with the compressor off but will drop when the compressor turns on. Can you tell us what your low and high side pressures are with the compressor running?

It honestly just bottomed out the gauge when the compressor kicked on. It would stay on for about 2-3 seconds then turn off. When the compressor turned off the gauge would just shoot straight up nearly maxing out the gauge before the cycle would repeat. I don't know if it hit a specific number on the high side I can check tomorrow ,but it basically would bottom out (on) then max out (off)

 

[rymax101]

Sounds like low charge.

Sent from my HTC6545LVW using Tapatalk

 

[keith89]

Yea definitely low charge. The pressure will drop and when the pressure is too low on the low side, the compressor will turn off. At least you know the low pressure cutoff switch works fine.

Get a leak finder kit with the UV light and glasses. Check for leaks around all the fittings especially at the compressor.

 

[GDDYUP]

If you take it to have an A/C service done on it, they have to pull vacuum on the system once they remove any leftover refrigerant. They have to pull a vacuum on the system to ensure there is no moisture in it. If you have a leak somewhere it will typically show up during that process. If there's a leak, it won't hold vacuum and then you go looking for it with dyes and such.

 

[Doc Voliday]

Thanks guys I'll probably take it to have it looked at like I said I'm no AC pro by any means. I guess the part that was concerning me and stopping me from just throwing some charge on it was the pressure gauge just sky rocketing all the way up when the compressor kicked off.

 

[RichM1983]

What kind of gauge are you using? Have a pic?

 

[Doc Voliday]

Just the gauge that comes in one of those refill kits at autozone. I don't have it in hand and I've had it for a while. I'd have to go look at it again.

 

[zredfire04]

you're in luck.

i repair hvac for a living. (actually ice machines and commercial refrigeration, but whatevs)

the "gauge" you're using only reads low side pressure. since the compressor is short cycling, and the gauge is doing what it's doing, it most likely means it's low on refrigerant. your best (read: least expensive) course of action at this point is to go buy a can of 134a that has leak detector dye in it and put enough in there so the compressor will run normally.

if the leak is bad, the compressor will start acting up again and your a/c will quit pretty quickly. it's then just a matter of looking for the green stuff. a common leak point is the service access ports, so be sure the caps are on and tight. if it takes months to leak out, keep putting in the 134a w/dye until you can find the green spot. if you can't ever find it under the hood, it could be the evaporator that's leaking.

also, since there's still pressure when the system is equalized, the odds of having a bunch of noncondensibles in the system are low.

hope that helps. if you have any problems with the above, PM me.

 

[Doc Voliday]

I put a 12 oz can with the dye in it last night and it seems to be doing well so far. I don't think that was enough though. It needs a little more.

 

[dom418]

Leaks are very common on these. All 3 of mine leaked at some point and needed a recharge. One had just 2900 miles and it leaked out. You have to use the AC a lot to keep all the O rings lubed