A/C question

[George Blake]

Weird thing happened. Using A/C. Worked great. Dillon and I drove about 300 miles. Hottest day of the year. Last leg of the trip going to Dayton. Air gets friggen COLD. Drive it back home. Still friggen cold. Colder than normal. Engine temps go about 30 degrees over normal. Get home, open the hood to let the heat out.
Next day. NO air. Vents and everything work, just no cold air.
Thought my freon was low (converted to 134A about 8 years ago).
Went to put the gauge on the LOW side and the friggen needle flips ALL the way around to past 90 psi. Turning on air, got NO compressor engagement.
One of the guys at Napa tells me the little orifice screen is probably clogged.
Said to replace that, the dryer, pull a vac on it and refill it.
Does this sound right?

 

[EcSy#2671]

Re: A/C question

You are low on Refrigerant or the low pressure switch is bad, What happens went your feron starts to leak the pressure drops as the freon level drops in till there not enough feron to trip the low pressure switch. If you Hot wire the low pressure switch the compresser will turn on. The low side pressure to below 40 psi but above 25 psi.

 

[supersports10]

Re: A/C question

You are low on Refrigerant or the low pressure switch is bad, What happens went your feron starts to leak the pressure drops as the freon level drops in till there not enough feron to trip the low pressure switch. If you Hot wire the low pressure switch the compresser will turn on. The low side pressure to below 40 psi but above 25 psi.

x2 on this. when the compressor is not running, the low pressure side will show very high pressure.

 

[0966Sy]

Re: A/C question

Check power to the compressor? If you got power and your charge is full, then you need to test the high/low pressure switch. They are adjustable, there is a little flat head screw there for adjustment on cycling the compressor once the low side reach's the specified pressure. I have mine adjsuted to 25-30psi i think wile running on max. You dont want the compressor to cycle to fast, just enough to keep the evap from freezing. Adjust till you reach compressor clutch shut off at specified psi on low side. differant climates will affect this adjustment. watch your temp guage inside, and start adjusting on max ac full blower. try to keep it around 40-45F. Cant get the compressor to work? jump it to check your charge, If charge is good try a new high/low switch. Doesnt jump? bad compressor.

 

[SBNova]

Re: A/C question

After my dilema with AC compressors, I finally have my system vac'd and filled. I got a used compressor from a member here. He pu plugs in the holes for shipping to keep any oil from leaking out. I removed the plugs and maybe a drop or two came out with it upside down. It didnt seem to have much in it. I hooked it all up and vac'd it to -30 over about 5 minutes time. I had also thoroughly flushed all the lines and changed the orifice and drier.

So when I bought freon (134a) I picked up one can of 134 w/stop leak, and a can of 2oz Esther oil w/1 oz 134a in it since I was unsure about the oil quantity.

I start the truck, with the AC on high. As I added the oil/134, the comprssor started to cycle, but very quickly. Then I added the 13(?) oz can of 134 w/ stop leak, and the compressor was running solid. If I upped the idle speed, it would shut down. So I put a washer under the idle screw which raised the idle to 1500. At this speed, I added more 134a, maybe a half 13oz can, and the compressor would just run solid, at about 25-27 psi on the low side. It seems to cut out at 25.

The problem is my vent temps are only 56-60 at best. Any less freon and the compressor doesnt run much. I didnt think (by quantity) that I put too much in. Theres 3oz of oil/134, 13oz of stop leak/134, and maybe 5oz of straight 134 for a total of 21 oz. Does this sound right?

Should I have added the oil? Is this too much or not enough oil?

 

[George Blake]

Re: A/C question

Well, my stock compressor seized up.

Jimmy Mann is sending me another.
I'm gonna swap out the dryer and the orfice screen.
What do you guys "flush" the system with?
I'd like to flush out the everything while the dryer and compressor are off.
If this goes out after redoing it again, the ac is gone. Last time last 8 years. It just failed at a bad time.

 

[SBNova]

Re: A/C question

While I had the system apart I flushed it with a mixture of purple stuff and water first, untill it rinsed clear. I would fill the system in halves- the condensor half and the evaporator half, disconnected at the drier and the compressor. I filled it up, then blew it out with my compressor and repeated, numerous times. I put the rinse water into a bucket and let it settle to make sure it was clear. Since purple stuff is hard on aluminum, I then rinsed with plain water quite a few times. Then I blew it out thoroughly, and it sat for two or three days and I blew it a few more times again. No vapor came out at all at this point.