Best approach for fixing inop R12 A/C system

L31MaxExpress said:

Personally I would want the 34" wide condenser core if you have a 34" wide radiator core in that truck. I would also use the Yellow 0.062" GM orifice tube listed for a 1999 Suburban. Does your 93 have the auto recirculation pressure switch on the condenser?

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Leeztruk said:

You're a brave man to change that evaporator. I do believe the WHOLE dash has to come out to gain access to it. If you could get the line from the evap core to the accumulator off, then flush the core and leave it alone. Same for the liquid line. If it comes loose, just flush the old oil from it and use it, unless it's so corroded it's beyond use. Just trying to save you some time and bucks

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someotherguy said:

I recall you mentioning that condenser but I'm thinking it really shouldn't be necessary for a regular cab truck. I can absolutely see where you want all you can fit in there when you're cooling down a van or a Suburban (or even a crew cab.) My truck has the full height power steering cooler on the driver side and I'd rather not mess with trying to relocate and cause more issues, as it's currently sitting in front of the radiator core and I'm sure would need to move to run the wider condenser.

The orifice is an easy one to add of course, drop in the bucket cost-wise.

The switch is the puzzling thing to me. There's no switch or place for one on my condenser. Additionally, there's only 2 switches in my system. The low pressure switch on the accumulator, and the high pressure switch that is in the compressor. The hose manifold has the high side port on it. This is a different arrangement than my old '94 C2500LD which had that 3rd switch hanging off the hose manifold:

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You're right, the dash absolutely has to come out to change all that mess. However, my dash is totally destroyed and I have a replacement sitting on my worktable that needs to go in. It would be crazy for me to skip the chance to crack open the HVAC box and clean it out while I have the dash off. Moreso, to not replace the evaporator while I'm in there. I've had a few of these dashes out as well as HVAC boxes out and split open for cleaning. Not fun but not terrible. Crap that just reminded me I need to replace the recirculate actuator motor, another part for the list.

Key phrases from your reply: "if it comes loose" - there's a lot of corroded stuff under this hood. We don't really get rusty vehicles down here in SE TX but this truck looks like it may have sat in a field for several years so moisture from the ground attacked everything. Each time I work under the hood on on the suspension, I have to wonder about what fastener will seize or break next. I don't have much faith in the A/C parts coming loose without damage.

I could be wrong and I'm waiting for someone to chime in, I think the threads are different on the R12 vs. R134a stuff - SAE to metric - I think @Wildblue19 mentioned that. So while I'm changing other parts I don't want to get into a thread mismatch battle.

Richard

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grampadirt said:

Looks like you have it all figured out pretty well,looking forward to seeing how it turns out.To me the cost of having a new a/c system is not too bad and is money well spent.When you're done with this truck it's gonna be a nice one

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someotherguy said:

I'll wait a couple days before I hit the button on the amazon order as I don't need them waking me up with the doorbell just yet

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