Anybody close that knows A/C

[red71cheyenne]

I have the Oldair system installed and tried to charge it myself. The compressor keeps dragging though, so I think I have some air in the system. Anybody close that has the tools to evacuate and re-charge? I'd really like to learn to do this the RIGHT way myself. Thanks, Jeff.

[red71cheyenne]

Maybe have to jury-rig something. ttt

[kevmic28]

Harbor freight sells a nice little vaccum system for pretty cheap. Might try that route before you jerry rig something.

[JimKshortstep4x4]

I assume that Muskegon, MI is too far for you!

I don't understand your comment on the compressor "dragging". Can you elaborate?

Jim

[red71cheyenne]

The compressor was running, but would act like it got a restriction and would cause the belt to slip/drag. Made a horrible racket. I tried evacuating the system again, got it to 25 inches of Hg for an hour and then put about another pound of freon in it. Everything was ok for a bit, but then it started slipping/dragging again. With the pressure guage on it, the pressure would gradually rise until it was around 80-100 psi. When it wasn't dragging, the pressure was around 20-25.

I'm not sure what to think. I'm going to call Oldair Monday and see if they have any idea's. Seems to me I've got air or something, but like I say, I got a real good vacuum on it.

[crushermechanic]

the only reason the compressor will do that is a loose belt or the compressor is locking up. are you hooking your gauges on both sides of the system high and low. you should see about 200-225 an the high and 25-30 on the low.

[red71cheyenne]

I only have one guage for the low side, no high side. Would air in the system cause the compressor to lock up? I can't imagine anything being left in the system after the vacuum. Might the compressor just be bad? Why would it go back and forth? Belt is tight. I thought that might be it too, but I have it tight.

[crushermechanic]

no air wouldnt cause that. did you put oil in the compressor? i have had a bunch of compressors bad right out of the box. what type of compressor is it? sanden or a-6?

[red71cheyenne]

Nope, didn't add oil. When I asked Oldair about it they said it already had oil in it. Its a NBW? Made in China. They said I didn't need to add oil, so I didn't. I'm calling them again tomorrow.

[Richard H.]

I pull the hg down to 29+ for an hour and then let it sit an hour to see if it holds for leaks.
It is 134A why reclaim it? 1.8 lbs should be enough freon 134... Vintage air has a good download for start up charging. I think you have a moisture issue.. you need more vacuum , the water won't boil at 25.

[Ackattack]

I'm going to borrow a buddies A/C tools sometime in the near future. I think it has 2 guages, so let me know if you don't get it figured out and maybe we can get both of our systems charged.

BTW, how much freon are you supposed to put into the system?

[red71cheyenne]

The instructions say 26-32 ounces. I'm only getting one can(12 oz) in when the compressor goes haywire. Richard H may be right, maybe I didn't get it down far enough to make sure all the moisture is out. I'm still going to call Oldair tomorrow to ask about the compressor tho. I'll update you as to what they say.

[red71cheyenne]

Originally Posted by Richard H.

I pull the hg down to 29+ for an hour and then let it sit an hour to see if it holds for leaks.
It is 134A why reclaim it? 1.8 lbs should be enough freon 134... Vintage air has a good download for start up charging. I think you have a moisture issue.. you need more vacuum , the water won't boil at 25.

Richard, I understand what you are saying about the vacuum, but what do you mean about the water boiling? Will you see the water vapor coming out?

[crushermechanic]

you wont see any vapor coming out but it will dry the system out 29" of vac. it also sounds like the compressor is cycling normally just not enough freon in it. have you tried charging it with it running? it will pull the gas in.

[red71cheyenne]

Originally Posted by crushermechanic

you wont see any vapor coming out but it will dry the system out 29" of vac. it also sounds like the compressor is cycling normally just not enough freon in it. have you tried charging it with it running? it will pull the gas in.

Yes, this whole process was with it running. Except the vacuum that is. The compressor runs constantly once it gets enough freon in it. Its just locking up at certain times.

[mrein3]

Originally Posted by red71cheyenne

Richard, I understand what you are saying about the vacuum, but what do you mean about the water boiling? Will you see the water vapor coming out?

For those of us that slept through high school chemistry...

Pressure and temperature are related. If you lower the pressure enough you lower the boiling point. When you drop the pressure in the closed AC system to -29", the water that is in there will boil away and leave you with no water in the system. At -25" you didn't get all the water out.

And no, you won't see steam coming out.

Like Richard H. points out, your process should be:
1. Pull -29" hg.
2. Shut the valves on your gauges and remove the vacuum.
3. Wait an hour.
4. If you are still at -29" hg, charge the system. If not, find your leak, repair it, and go back to step 1.

[red71cheyenne]

Originally Posted by mrein3

For those of us that slept through high school chemistry...

Pressure and temperature are related. If you lower the pressure enough you lower the boiling point. When you drop the pressure in the closed AC system to -29", the water that is in there will boil away and leave you with no water in the system. At -25" you didn't get all the water out.

And no, you won't see steam coming out.

Like Richard H. points out, your process should be:
1. Pull -29" hg.
2. Shut the valves on your gauges and remove the vacuum.
3. Wait an hour.
4. If you are still at -29" hg, charge the system. If not, find your leak, repair it, and go back to step 1.

Thanks for the explanation, that clears up a lot! Now just have to locate the tools. Jeff.

[leddzepp]

Originally Posted by red71cheyenne

Nope, didn't add oil. When I asked Oldair about it they said it already had oil in it. Its a NBW? Made in China. They said I didn't need to add oil, so I didn't. I'm calling them again tomorrow.

I have an OldAir A/10 replacement compressor (replaces the old A/6) I had to add oil to it, it was shipped dry.

I have never bought a compressor in my life that came with oil in it. I would check to make sure it has oil in it before you burn it up. No oil would cause exactly the problem you are describing.

My .02

[mikemileski]

As CHARGERMECHANIC stated earlier, the dragging isn't related to not evacuating the system. Something else causing it.

Mike Mileski
Tucson, AZ

[red71cheyenne]

Originally Posted by leddzepp

I have an OldAir A/10 replacement compressor (replaces the old A/6) I had to add oil to it, it was shipped dry.

I have never bought a compressor in my life that came with oil in it. I would check to make sure it has oil in it before you burn it up. No oil would cause exactly the problem you are describing.

My .02

Thanks guys. I called Oldair and they need pressure readings to give me an opinion. Waiting on guages and a new vacuum pump to arrive now. How much oil should have been in the compressor? Oldair said not to add any, it already had it, but now I'm beginning to doubt that it had any in it.

[Richard H.]

You won't be sorry getting the right tools for this ,they come in handy down the road.I got screwed once on having my hoses crimped....I bought my own crimp tool.
How do you like that Camaro?

[red71cheyenne]

Originally Posted by Richard H.

You won't be sorry getting the right tools for this ,they come in handy down the road.I got screwed once on having my hoses crimped....I bought my own crimp tool.
How do you like that Camaro?

There ain't no way I'm sticking my fingers in the Camaro. I love it, and I'd hate to screw it up. Its got almost 3000 miles on it now!

[Richard H.]

Originally Posted by red71cheyenne

There ain't no way I'm sticking my fingers in the Camaro. I love it, and I'd hate to screw it up. Its got almost 3000 miles on it now!

The guy ask me when I bought mine if I wanted to look under the hood...I said no that would be the service managers job
800 mi and counting.

[red71cheyenne]

Well, just to update, I got the A/C guages and vacuum pump from Harbor Freight and tried to charge again. Still no joy. So I called Oldair and they said it sounded like I needed a new compressor and drier. They are sending one out. They said I would need to flush the system before charging again. How do you do this? Thanks for all the help guys. Jeff.