AC Compressor Question
 

Simple question: How can I tell if my A6 compressor is good?

Detailed question: I'm going through the AC on my 72 c10 with all factory air.
I've replaced all vacuum lines, cleaned out every orifice and everything appears to be functioning correctly. (compressor clutch kicks on, kick panel vent opens as designed, blowing through the correct vents, etc.) The system is still R12 and before I make the R12 investment :), I want to make sure my compressor is functioning as it should.

I placed a set of gauges on the unit and while running both Hi and Low read zero. I also used a HVAC sniffer (very cool tool!) and found no leaks in the system. (I have a vacuum pump and will also pull a vacuum to see if I can identify a leak) Last question, any thoughts on a rebuilt A6 (RockAuto $140) vs a new Delco ($400) I understand the rebuilt A6 compressors tend to leak at the shaft because most have been rebuilt many times.

Re: AC Compressor Question
 

It may not be showing any signs of a leak because all of the the R-12 may have said "ADIOS"

Re: AC Compressor Question
 

I would never buy an A6 again. Nothing but bad experiences with them. Look into a pro6ten from old air products. I used one several years ago on a 72 I owned, and plan on buying another when I rebuild the factory AC in my 68. The only reason my current 72 has an A6 is because it worked when I bought the truck, and when I pulled the truck apart for restoration I knew it would work when I recharged it. If and when it bites the dust I will use a pro6ten.

Re: AC Compressor Question
 

If the compressor turns, you may not need a new one. Find and fix the source of your leak and then go from there. I would at least change the dryer if not the expansion valve too before I put it back together.

Re: AC Compressor Question
 

All the A6 comps leak from the shaft seal, new or reman. Even back in the day. The oil slinging onto a nicely detailed engine compartment is what guys really cant stand now days. People didn't care about that back then. That's a reason they had a wick installed to absorb some of that oil. But it needs to be changed when saturated or else the oil slinging will begin. Corvette guys love that oil on their fiberglass hoods, lol. There were even some shields that were used back then. A new a6 should have the wick installed but it should eventually start to sling oil after the wick gets saturated. The remans that ive seen haven't had the wick installed. The pro6ten does eliminate this issue. I have a shop and the guys ive sold those aluminum a6 replacements have all been pleased. and they are leass expensive than a new steel a6

Re: AC Compressor Question
 

But to help answer your question. Its a little difficult to test just the compressor while on the truck. Well at least for me anyways. I use to work for a company only does classic car a/c restoration and when we got a compressor in we would bench test it by putting it under load and check how well it sucked and pumped. I guess you could do that on the truck but you would have to disconnect the hoses from it

Re: AC Compressor Question
 

I've not had seal leaking problems with the A6, but will admit that it's a problem many hobbyists chase for years. I wonder if the newer replacement seal design is any better? I don't know because, as I said, mine doesn't leak!

Many guys swear by the A6 for it's primary responsibility: Compressing! It's good at that. It's also a HP user and there are certainly newer designs that are lighter and produce less drag. I'm stuck on the O.E. look, personally.

Back to the OP's question: As already answered, I'd first interpret a "zero/zero" pressure reading as an empty system. I have a nitrogen bottle and do a test fill with the cheap nitrogen to check such things. Even a low pressure charge of N2 and will give you an indication of a pressure differential, indicating that the compressor is... compressing.

Re: AC Compressor Question
 

Yea nitrogen is the way to go when checking for leaks.

Re: AC Compressor Question
 

If you want an A6, get one from John Deere. They are rebuilt in the USA and last for years. I have yet to see one leak oil either.

Re: AC Compressor Question
 

I've heard of the John Deere option but have not tried it. Can you just walk into the shop and ask for an A6 or do we need a part number?

Re: AC Compressor Question
 

You might find this helpful.http://aa1car.com/library/ac98.htm

Re: AC Compressor Question
 

Order it for a John Deere 4440 tractor or 8820 combine.

Re: AC Compressor Question
 

bump to find my way back. Gonna check those parts out.

Re: AC Compressor Question - UPDATE
 

Thanks for all the great ideas.

I have found the source of the leak. A pinhole on the condenser near the hi side fitting. I found it with a Nitrogen charge plus soapy water. After 36 hours pressure went from 165 pounds to 80. The condenser is aluminum, I assume better to replace than repair?? Can someone suggest a good quality OEM style condenser? I've priced them between $65 (eBay) and +$200 (LMC).

I also have a spare condenser that someone gave me. I'll pressure test that in the off chance it is good. Then flush... (suggestions on what to flush with?)

Finally back to my original question, once I have non leaking system, how do I test my compressor to see if it is properly compressing. All I can tell at this point is that it is kicking on (clutch spinning) when it should. Concerned about the efficiency...

Re: AC Compressor Question
 

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Re: AC Compressor Question
 

Are you using r12 or 134a? If r12, then an oe style tube and fin condenser is fine. But if you are going with134a then you want to use a parallel flow condenser

Re: AC Compressor Question
 

Where is the best place to get a parallel flow condenser?

Re: AC Compressor Question
 

I am still trying to source a factory bolt in parallel flow cond. But for now if I had to use one I would simply buy a universal that is the same dimensions. I can make then factory drier and lines work with it. Ive made custom bolt in pf condensers for a 68 chevelle, 72 442( they have since started manufacturing one) and a 71 GTO.

Re: AC Compressor Question
 

I installed this universal condenser (26x16) on my Suburban. I bought the largest one that would physically fit because I'm running front and rear air. I had to trim the latch support a little. I used the factory brackets with some spacers. Since the lines to not come out at a 90degree angle like the OE condenser, I had to extend the lines. I could have made the 3/8" line but I didn't have the tools for the 1/2" line. The welding isn't pretty but it's holding.

Re: AC Compressor Question
 

That's not bad at all. How much was that condenser?

Re: AC Compressor Question
 

I work on John Deere equipment, DO NOT get one from deere, expensive and it seems half of them leak out of the shaft seal before its even out of the box(they have a nitrogen charge from reman) If you want to get one for a Deere I recommend going through www.apairinc.com , they have good quality and cheaper than going though the John Deere dealer

Re: AC Compressor Question
 

I believe old air products carries one that bolts in.

Re: AC Compressor Question
 

I have seen some pics of it but not sure that's a pf condenser. It looks to have cylindrical tubes resembling the original tube and fin style, although smaller looking in diameter. Havent called them to confirm

Re: AC Compressor Question
 

This is a direct fit parallel flow condenser just haven't been able to confirm who makes it. And Old Air Products does not look like this at all

Re: AC Compressor Question
 

Really Cheap :mm:

They have hose and fittings also