Another AC question...

[tex_waco_usmc]

AC hasnt worked since I have owned the truck. Daughter is going to be driving it so....

What needs to be replaced? I have the complete system for the 87. But, being as it has sat unused for a long while, what needs to be replaced with new in an attempt to get the trucks AC to freeze you out of the cab? LOL

[tucsonjwt]

I am no A/C expert, but your first decision is whether or not to keep it R12 or change it to 134A refrigerant (assuming that it has not already been changed over to 134A.) Around here, you can still get R12, so I would go that way if it is still R12 - otherwise, you will/should add a "pusher fan" in front of the condensor and change the condensor to a "cross-flow" condensor.

I would first take the truck to a mechanic have an "A/C special", where they can pressure test the system and tell you what kind of refrigerant you have, then give you an estimate of what you need. Once you know what you need, you can shop for those parts online and try to find a mechanic who will install the parts and fix your A/C for labor cost only.

I would post back here once you have a list of what you need and get some expert advice.

[8lugnutz]

Agree with tucsonwt above, that's the first decision to make. Mine didn't work when I got it either, but all of the parts were intact, and mine looks like it has been converted to R143a. I've been working on mine this week and it still doesn't work, but I'm addressing that this weekend. There is a ton of information out there, but here's a couple of threads to reference:

Any AC compressor conversions for R134A?

and this one from another forum:

A/C How I Did It

[tex_waco_usmc]

I do know that I am going to convert to r134a just because r12 is difficult to come by around here. It has not been converted and I have the parts but it is completely disassembled at the moment. The belt is off the compressor and has been since I got it. Clutch feels ate up so I know at a minimum it'll need a new compressor clutch may just replace the compressor.
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[pontgta]

I would replace the accumulator, orifice tube, and the compressor(unless its new). Run a vacuum for about 45- 75 minutes. Check fro leaks. Then add 1 can of Freon and check for leaks. No leaks then go ahead and top it off... I would not mess with the R-12....unless its free. Yes will perform better, but will cost and then if you have a leak or run into any issues, it will cost you too much. I can not notice the difference in the 12 and 134a , unless i take an actual temp reading. also replace all the orings... if you have a union or it has threads, it will have an O-ring(lube them with refrigerant oil).

[tucsonjwt]

You can hold off on getting the pusher fan and cross flow condensor until you get the system working. The downside is that if you replace the condensor with a cross flow type after you have the system working you will have to evacuate and recharge the system at additional cost.

I added a pusher fan from a 98 Chevy metro I got from the junkyard and it helped with cooling at idle a lot. You can add that without messing with evacuate/recharge at a later date. I have a thread on this forum about using a relay and how to wire up a used pusher fan - my mechanic helped me and I think the whole project was less than $50.

I have had 3 squares and my experience is that R12 cools much better, but I live in Hotzona, so that pushes any A/C system beyond normal limits. R134A without any additional mods will work OK until it gets above 100 degrees, which most people never have to deal with.

[Edahall]

I'm using the old school freon in all my vehicles. In fact, I've converted several of my vehicles that were originally designed for R134a back to the old school stuff. It runs so much cooler. All my friends with new vehicles can't figure out when they ride with me why my A/C is so much colder than theirs.

[8lugnutz]

tex_waco_usmc, sent you a PM.

[rebootit]

r12 is hard to find and people still want stupid money for it when you do find it. An option is duracool. It is compatible with any oil, has almost the same head pressures of r12 and is much much lower than 134a. Cooling is very close to r12. I have used it for several years in my 82 Mercedes Diesel and now in my 76 c10. The c10 had all original AC components but had sat since 83. There was still about 30 psi in the system when not running so I knew it didn't have a big leak. It took 4.5 cans to bring it up to the correct pressure and has held for two months now. I'm in central FL and it really tests an AC unit. Moving down the road in the heat of the day I get 42 degree vent temps. If stopped for 5 minutes or so they go up to around 55 but drop immediately once I'm rolling again. 134a would never get that cold and would have really stressed out all the old parts. Best place to get it is online and cost wise your looking at around $8 a can.