Decided to be daring and try the AC for the first time since I got it running. Hadn’t been used since 2006 so didn’t know what to expect. Much to my surprise (dismay?), nothing happened. Clutch didn’t engage and nothing changed. AC is one thing I’m ignorant on and have no idea where to start looking. Any help or ideas? I know it’s got old 134 in it and I’m hoping to avoid upgrading it to the new flammable stuff but might not be possible.

Its an 89 built in 10/88.

 

The clutch won't engage if the refrigerant leaked out. If it's got R134A in it, you should be able to continue using 134. No need to convert to anything. Unless it originally had R12. Then you should convert to 134. Plenty of threads on how to do it.

If all the parts and wiring are still in place, it should just be a matter of freshening up your system. This is a good opportunity to learn about your system and save money getting it fixed yourself. Read up and come back with any questions. Good luck with it.

 

Don't use the "new" flammable stuff (a mixture of propane and butane). Not only dangerous, it isn't legal to use anywhere.

Here's everything I know about air conditioning: https://www.yotatech.com/forums/f116...-r134a-284801/ To confirm you're out of refrigerant, these are the gauges I used: https://www.harborfreight.com/r134a-...set-58776.html

Are you sure you have R134a? That wasn't required until 1/1/94 (my model-year '94, built in August of '93, had R12).

 

I assumed it was 134 as that's as far back as my knowledge goes. Maybe it's r12. Can't find a sticker anywhere that says one way or another. I wish the pictures in your other thread still worked. Good write up.

 

I'd hook up the service valves to the compressor and pull a vacuum, then let it sit. I let mine sit overnight, but i think most recommend an hour or so. If it loses vacuum you might have to replace the seals. Replacing seals actually isn't all the hard. If it holds vacuum than you should be good to go with recharging.
The parts stores probably have the ac charge valves in their loaner program. Vacuum pump, too.

 

I don't mind buying tools. Just needing a jumping off point to start checking things. It's starting to get hot and humid down here. Appreciate the help everyone. Certain I'll have more questions as I dive in to this.

 

Did some research and cleaned the core support and found the sticker that said it’s got r12. So looks like I’m starting down the path of conversion.

 

Find a parallel flow condenser and larger R134 compressor if they exist. R134 has different requirements and using it with R12 size components is going to give unsatisfactory results.

 

Fine works just fine with the same-sized compressor. Yeah, R134a is different from R12, but not that you could tell.

 

Makes a HUGE difference in cooling capacity. Getting the parts sized for R134 is the difference between slightly cooling and blowing ice cubes out of the vents.

 

Mine is all stock Denso/oem and I'm happy with the r134 performance.
My evap box was loaded with debris, I mean like half full. So replacing the seals had unintended benefits.

 

Parallel flow condensers do exist for these trucks. Haven't found a bigger displacement compressor yet. Maybe something off a Lexus of the vintage.

SPECTRA PREMIUM 73932 on RockAuto is a parallel flow condenser. That alone will be a nice improvement for R134.

 

i have a york compressor on the 22re, using a really warped adapter that i got off of craigslist probably a decade ago... here are plans to make the adapter here: https://www.yotatech.com/forums/f129...d-22re-163697/

 

Uhhh an air compressor? We are talking about AC compressors here.

 

wow, you never heard of york... they have been putting factory ac compressors on cars going back to the '60's, and that's what i have, it's an ac compressor being used for on-board air.

you wanted a bigger displacement ac compressor, york is it.

 

I was thinking a more refined option. Something that will bolt in to the factory location and use the factory line set and fittings.

 

Well, if you do decide to switch out your compressor I'd recommend keeping your old one. At the very least, keep the charge plates(service valves) that the pressure lines connect to. Those are gold these days. And reman units don't include them.

 

What’s a charge plate? I know what a compressor is.

 

I believe he's referring to the adapter to which the high and low pressure hoses connect. As Jimkola says, the replacement compressors don't have them.

 

Yeah, 88322 and 88332