89 f250 ac question

[Kraig]

Hello,
I have a friend at church who is a missionary. His AC is out and I am endeavoring to fix it.
Issues is, I cannot find the low side port. There is a port that has nothing on it on the accumulator but I can't find if that is where the low side port should be or where to buy one.
He's hitting the road next week and I'm trying to get him some AC before then.

Please help.

 

[Nero]

That system will have originally been R12. The low side port is on the accumulator. Chances are it still has just the old style threaded fitting. There's more involved than just refilling it, unless it's been up fitted to r134a already.

 

[Kraig]

I'm guessing someone either converted it or started to but there are two ports exposed on the accumulator. Does anyone have a pic to diagram on which one is which? Can I just get. R12-r134 conversion port to put there?

 

[Nero]

The port facing the fender is actually for the low pressure switch. The other port facing forward-ish is the service port.
If the low pressure switch is missing, the system will not function.

 

[Nero]

You must be registered for see images attach

 

[Booyah45828]

If he's missing the conversion ports, the retrofit was likely never done IMO.

If you're unfamiliar or inexperienced with refrigeration or the process, IDK if I would do this if I were you. I get helping out a friend and all, but this will be more then just add a can or two of gas, and it might turn into a can of worms you don't want to open.

 

[DrCharles]

Good advice... it may have just had a wallyworld "death kit" (two cans of R-134a and some compatible oil), and the original oil, that is not miscible with 134, sloshing around taking up space somewhere. Among many other nightmare scenarios.
I wouldn't touch an unknown setup like that without flushing the entire system, changing the compressor oil, replacing all o-rings and leak-checking under pressure, at a minimum.

 

[tbowker]

Miscible. I had to look that up to be certain that was even a word. Some pretty smart characters on this forum.

 

[Tristan]

Miscible. I had to look that up to be certain that was even a word. Some pretty smart characters on this forum.

well, he is a Dr.

 

[franklin2]

Good advice... it may have just had a wallyworld "death kit" (two cans of R-134a and some compatible oil), and the original oil, that is not miscible with 134, sloshing around taking up space somewhere. Among many other nightmare scenarios.
I wouldn't touch an unknown setup like that without flushing the entire system, changing the compressor oil, replacing all o-rings and leak-checking under pressure, at a minimum.

Sounds like a nightmare, but it works. Old hoses, old o-rings, ester oil. I have heard of people not even evacuating, just adding the 134a on what little r12 was left. I would not recommend doing that, but apparently people have tried it and it works.

I have done several by installing conversion fittings, evacuating, checking for leaks, and then adding the r134a/ester oil combo cans and had them work well.

 

[tbowker]

well, he is a Dr.

Yeah, those guys know stuff.

 

[Kraig]

I have done many ac systems. I was just looking to make sure go the old setup was. I will be draining, flushing and te sealing the whole system, and replacing the orifice and accumulator. I was thrown off when I couldn't remember where the low side port was on this truck. I should know j used to have one myself.

Thanks for the advice. I am praying I can get tho done for him. The ACTUAL temp today, for example, is 103deg. So he needs some AC for his long drives this coming fair season. Lol

 

[gnathv]

You say there’s nothing on the accumulator ports, is the low pressure switch missing or just laying somewhere nearby?

 

[Kraig]

The switch is there it's the low side port that's missing.

 

[gnathv]

If the port is missing you’ll need to bypass the switch.