AC questions

[CharlieC]

I have an AC system pulled from something in the early ‘80s and installed it in my ‘74. Last time it worked was 1989/90 and worked pretty well, had a leak and never fixed it when the K5 was relegated to part-time driver. It had the old A6 compressor, which that and the hose assembly that connected to the dryer/condenser are long gone. Whats left has been ”open” 20 years probably since I didn’t seal anything up.

If I’m thinking of getting the AC going again, is it worth trying to revive what’s there vs buying a kit? I do have a new March serp kit I bought 10 years ago still sitting in the box with a compressor. Think it’s still good?

Thanks
Charlie

 

[Wes Harden]

The compressor is a high candidate for the leak, A6 have weak front seals.
Four seasons makes an updated a6 replacement. Rock auto will have a kit, compressor, accumulator, orfice tube. This for you will need.
If your condenser is gone or damaged, you'll want to find one first. For whatever reason they are unobtainium ATM, and $300-$400 new if you can find one.
Once you have the condenser, get your kit. Then source the hoses from compressor to condenser and accumulator.
If you get the a6 replacement and a factory condenser the factory hoses will work rock auto has that too.
You will want flush the remaining parts that where left open with an a/c system flush.
Then once the system is complete and sealed vacuum it down for a hour or so to dry out any moisture.

 

[CharlieC]

To be specific… last time it was run was maybe 30 years ago, it was opened when compressor/lines were pitched 15-20 years ago I guess.

I do have the OE condenser still in place. I take it you cannot use that with 134 given comment above?

The controls should work, assuming I can flush condensor and evaporator. if we assume everything was going to work, what needs to be changed to run 134 or whatever the new Freon is?

The March kit I mentioned before has a Sanden 508 ( I assume 134), given I have the brackets for it, could I use it?

thanks
Charlie

 

[Wes Harden]

It will work. It will need to be flushed well. Nice thing about the original condenser is you can flush them. You can't flush the parallel style. 134a is not as efficient as r12, so a bigger condenser is ideal. but the factory ones are pretty dam large, but the gas path has to pass all the way through the condenser. Possibly over cooling the the compressed gas.
I have done more than a few conversion w/o changing the condenser, worked fine in southern Cal.

I considered swamping mine this last spring, I couldn't find either style all out of stock. Our Canadian Brothers can get them thou....

 

[Wes Harden]

Sanden has renumbered their compressors. I recommend the SD7 series and the SD7H15, largest cc's. I believes these are the same physical sixe and mounting as the 508. Neither will work with factory A6 brackets.

 

[Wes Harden]

https://www.amazon.com/Four-Seasons-58098-C-Compressor/dp/B004AF52W2 will bolt right into the original A6 brackets

 

[CharlieC]

Thanks for all the info, last question…

My K5 did not come with factory air and I don’t recall what I did with the standard heater opening In the firewall. Anyone have a pic of what it’s supposed to look like? Any changes on the interior firewall? Seemed like I remember there being a replacement to to the manual vent doors in the footwell area. I didn’t change those, manual ones still there.

Thanks
Charlie

 

[Wes Harden]

There is a vacuum pod on kick panel fresh air door, to close it for Max Ac, and open for defrost and vent. not sure about other settings

picture is a factory ac truck that had pas-side r4 compressor. Fire wall set is basically the same if not exactly.



edit looks like has rear air so extra pipe in picture you shouldn't have

 

[Wes Harden]

yes definitely use the blue orifice tube. Not arguing, biggest cross flow condenser you can find.

I had heard some complaints about the VA condenser being undersized for K5's and bigger trucks so after some looking around on their website I found they make one that's almost the same size as our factory one so I ordered one off of Summit to try out. It'll be a while before I get everything put back together and running but here's what it looks like compared to the stock condenser and the one that comes with the VA sure fit kit as well as my mock up solution so far.

https://www.summitracing.com/parts/vta-037030-ovr

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nice comparison of condensers