1973 F100 AC question

[moveoverGM]

Hello friends. Recently bought this 73' F100 and everything works except the air conditioning. I took the truck to my local mechanic (who also collects and restores classic cars) and he told me to take it to an AC shop that it needed to be upgraded. My question is: Will the whole unit need to be scrapped or can this be made to operate again? Summer is coming and it would be nice to have it operating. Thanks for any info. Donald.

 

[Fellro]

For the most part, the upgrade consists of clearing out the old and in with the new. There are some off the shelf kits that have a conversion oil in them that lets the seals and orifice tube survive with the new oil. There are varying opinions about the use of said kits, as some will say you need to change all the seals and the compressor and such. I will just say that I have done quite a few conversions with those kits and been fine. My 86 actually has both the old and new refrigerant in it. First thing to do though is have it leak checked, which is just apply vacuum and see if it leaks. If it does, then the fun begins trying to find it.

 

[moveoverGM]

Fellro, thank you for your reply. I guess I will need to start with the leak test first. I wasn't sure if I had to change the whole thing which I suppose would be
pretty costly...

 

[Fellro]

When the change over first came out, that was what was said, that nearly the entire system had to be replaced. All o-rings, compressor, orifice valve, and dryer. The conversion kits that came out later have had mixed reviews, but so far I have been fine with them. The key is the conversion oil. Without it, there is a good chance you will have troubles if there is any of the old refrigerant left. Of course it is also possible you have an electrical issue, but it isn't uncommon for systems to leak down after sitting for periods of time.

 

[moveoverGM]

Yikes!! I have been reading up on AC changeover for my truck. At any rate it is involved and costly. Maybe I should just remove the entire system and drive with the windows down!!

 

[Fellro]

the kits I speak of are about $50. If it is a choice of rip it out or try that, I figure might as well try, worst thing can happen is you still just roll the windows down...

 

[Lorddurock]

a/c is something you dont want to skimp on during repair. you can do it from home, with a few tools from harbor freight.

this is a good friend of mine who makes very detailed how to videos. almost all of what you see will appliey to your truck and many other a/s systems.

https://www.youtube.com/watch?v=JVA5LPS34MA

one a side note r135A is smaller on a molecular level then r-12 i would recommend replacing the rubber hoses, changing all the orings and using ester oil are the lubricant.

 

[moveoverGM]

I agree 100%. Really, nothing to lose. On that note, this morning I decided to go see a mechanic friend who has worked on my cars before. He said he has done the kit route with good success. He said it would be about $200 to do the conversion and then test for operation. I figured that is not bad.
With that said, when he heard that it was a 1973 he went outside to get a closer look. "This is a really nice truck! Where in the world did you get it?".
He liked the story and appreciated the fact that I would trust him with it.

Donald

 

[Ozzie]

I recently refurbished the factory A/C on my '76 F250. The compressor is similar to yours except it runs horizontally. The only problem was the compressor's shaft seal was leaking (oil & refrigerant). Bought a new one at Auto Zone (under $15), replaced it, replenished the missing oil in the compressor with some old Ford oil I had, changed the drier ($12 @ Rock), evacuated the system, and recharged with some old R-12 I also had, and all has been working well since. Whatever you decide to do, be sure to run the A/C compressor for at least a few minutes every month during the winter. Some shaft seals require the presence of the oil to hold tight; otherwise you may loose the charge.

 

[moveoverGM]

Thank you Ozzie! Great information. I am glad I am on this forum!
Donald.