Air conditioning Reinstalling

[Captkaos]

If the system has been open for any amount of time replace the dryer.
The low side is on the dryer.
They make a kit that will allow you to repair the line for broker orfice tubes.
The compressor is most likely NOT completely filled with oil. You need to make sure.  It should tell you the amount for your system with that compressor.
You are going to need about 3 10oz cans to fill the system.

[1979C20]

I bought a dryer, orifice tube, and ac flush. I have to repair the orifice tube line, im buying the kit today. And the compressor said it was prefilled with 10floz or double end capped PAG oil. I will chack and make sure it is full, how do I check? Thanks capt.

[1979C20]

Thanks jason, ill check tonight. I bought the r12 to r134a fittings, and when I take my truck to a shop to draw a vacuum on it I will have them fill it with r134a.

[Captkaos]

There should be a chart indicating how much the system takes (oil wise) it should say how much is in it.

You can get a vacuum tool from harbor Freight for $15:
http://www.harborfreight.com/air-vacuum-pump-with-r134a-and-r12-connectors-96677.html

[Jason S]

The GM manual says for the A6 compressor system, there should be 10 oz of oil for the whole system.

 On an operational system, there would be a total of 6 oz. of oil in the accumulator and/or compressor (e.g., could be 3 oz. in compressor and 3 oz. in accumulator), 3 oz. in the evaporator and 1 oz. absorbed by the accumulator desiccant.   If your system is completely free of oil, then the compressor has the correct amount. That is presuming the system has been purged of excess oil, though.  If you have replaced the accumulator (filter/drier) and the oil drained/purged from the evaporator, condenser and lines, you should be alright.

You could drain the compressor, then add 4 oz. back, add 3 oz. to the accumulator and the remainder to the evaporator.

Many parts stores (autozone) will rent the tools you need, you just need a credit card. If you go that route, get the 1) vacuum pump and 2) line and gauge kit

[1979C20]

Well, I think the compressor is full. It says on one of the sheets in it that its preffilled with 10floz, and there is no leaked out oil on the compressor anywhere. The box was unopened when I got it. The ac systen was open for over a year, I removed the compressor when I got the truck in march, so most of it has drained or evaporated. Im going to be flushing all of the lines with a flush solution and a compressor. Then im taking my truck to my friends dads shop and im going to have him pit a vacuum on it and then fill it. And he'll do it for pretty cheap, ill probably just have to buy the refrigerant. I got my evap line fixed. Bought a orifice tube repair kit, cut the line behind the hole, put a nut and ferrule on the line, then flared it with a flare tool I rented. I bought a pack of orings too. So now I just have to flush all of my lines, flush the evap core, and flush the condensor tomorrow. Then install the new drier, put my orifice tube back on, and install all the lines with new orings and crush gaskets on the compressor lines.

[ehjorten]

Somebody school me, but I thought you were suppose to use Esther Oil on a R12 to R134a conversion and not PAG oil.  If you use PAG oil, which is what OEMs use, you have to be sure to drain all of the old mineral oil out of your system by taking the components off and manually draining them.  PAG oil does not mix with mineral oil.

[1979C20]

That is why I am flushing all of the components. All the lines, the evap core, and the condensor. Everything else is new. I should be able to get out a lot of the original oil, and I belive I minute amount left wont hurt anything.

[1979C20]

Okay, I talk to my buddies dad and he said he can draw a vacuum and fill my ac for 50 bucks. I just flushed out all my lines and evap core and condensor. Im going to replace all orings and the crush gaskets on the compressor lines. I have pictures to post tonight.

[Dr_Snooz]

Somebody school me, but I thought you were suppose to use Esther Oil on a R12 to R134a conversion and not PAG oil.  If you use PAG oil, which is what OEMs use, you have to be sure to drain all of the old mineral oil out of your system by taking the components off and manually draining them.  PAG oil does not mix with mineral oil.

Yeah, you want to avoid PAG oil. The double end capped PAG is compatible.

I don't recommend that Harbor Freight vacuum "pump." It's a venturi mechanism, which means that it draws a vacuum by you blowing compressed air past it. It got my pancake compressor very hot and never was able to pull the system down to 30 Hg. I took it back and got a proper pump from Napa.

[1979C20]

Thanks for the info snooz.

I have 2 questions. My clutch wont engage when I move my controls. I checked the clutch by jumping it to the batter and it worked. I bought a blower motor relay because I dodnt have one previously. I jumped the high side pressure switch/clutch cycling switch and the clutch still did not engage, woth the key on and the control set to max ac and cold. when I connected my blower motor relay, I can here a slight hum/whine from the blower motor but.it wont angage on any setting. During the winter I ran a toggle switched power wire to the motor for heat. So my questions are....

Why wont my blower motor engage, and why wont my ac respond to the switch?

Fuses are good, I checked wires and theyre good from what I can see.

[Captkaos]

I have pulled 3 systems down with that vacuum pump recently.

[78 Chevyrado]

easiest way to check if your pressure valve is working right is to pull the plug off it and short the 2 terminals out in the wiring plug.  if the compressor wirks after that, either the switch is bad or the sensor isnt getting any pressure to it.  sometimes the sensor doesn't reach the schrader valve under it enough to open it.  that usually happens when its over-tightened in the hole.

[1979C20]

78 chevyrado, There is no refrigerant in my system, so it has no pressure. I had to jump the pressure switch either way to see if the clutch engaged. And I still havent gotten it to work

[1979C20]

Just a few pics of my orifice tube repair and my new compressor installed.

Compressor


New flare where I had to cut the line


Liquid line side


Evap core side


Installed



And Here is my 2 minute home made flexible funnel so I could poor the AC flush in the lines
     I cut the bottom(if held right side up) of the bottle off so I could poor into it.