Convert 1989 to 134a ...a couple specific questions

[Jeepwalker]

Hey guys, first post. Not sure this is the right place plz move if it's not:

Several yrs ago I had my 89 "converted" to 134a. The shop flushed the system ..replaced the dryer, orifice, switch, orings, etc. We were going to replace the compressor but as I recall there was a shortage due to a heat wave. We used the original one, and 'believe' they may replaced the shaft seal. Predictably it lasted a week ..and never cooled very well even out of the chute. And I believe there was a leak at one of the o-rings, now that I look at it. We kind of half-did it ...mostly my fault bc I was in a rush to take it on vacation at the time.

So to pick up and do a better job ..and get some good cooling out of it, I plan to make a salvage yard run. I know the owner and can get the parts real cheap ..and it's a mile away from me. I'd like to have discharge temps ~40* or so. Let me ask the following questions get your collective expert opinions on the parts I should get. Plz note, I'd like it to look as stock as I can:

1) What year/vehicle should I get a condenser out of? (mine has a 5.7L). Will it be mostly drop-in? I've heard 97 and later are good.
2) Will the original evaporator work ok, or best to replace it? Mine already has a 134a like-new dryer on it ..so if I can keep the evap core that would be really helpful. If you don't suggest so, whats the best year/vehicle to remove one from?
3) Can a re-manufacturered 134a compatible FourSeasons R4 compressor work/last ok (provided I use the correct oil)? Because I already have one in the box downstairs. Bear in mind, in WI we don't have high cooling needs ...like a couple months/yr ...and this is an occasionally-driven tk anyway.
4) Should I scarf refrigerant lines off the truck too?
5) Will the original (stock) fan/clutch work fine? Nearly all my driving in this truck is highway miles. No sitting in traffic.
6) We can save the oil amounts and types later on ..unless there is a really good guide you can refer me to. Right now I'm more interested in what type/year vehicle I should get parts out of.

Thanks,

 

[PlayingWithTBI]

1) What year/vehicle should I get a condenser out of? (mine has a 5.7L). Will it be mostly drop-in? I've heard 97 and later are good.

Personally I wouldn't touch any A/C parts from a boneyard. Get a parallel flow condenser for your year truck since the position of the lines changed from year to year.

2) Will the original evaporator work ok, or best to replace it? If so, whats the best year/vehicle to remove one from?

It's probably still good as long as it doesn't leak and it's properly flushed. You may have to clean out the heater box if it's partially plugged with debris to help in better air flow.

3) Can a re-manufacturered 134a compatible FourSeasons R4 compressor work/last ok (provided I use the correct oil)? Because I already have one in the box downstairs.

Probably, but make sure you have the proper high pressure cut-off switch for it. Usually they don't come with one.
Here's a thread I started 3 years ago which may help.

How does the AC system work in early OBS models?

I've been searching for answers on how the AC system works in my 88 C1500 Silverado. Some places I read newer models that have the "re-circulation" button will open the door by the blower motor to get more cab air (when the AC is turned on), however FWIU the earlier models, like mine, by...

www.gmt400.com

 

[L31MaxExpress]

NEW parallel flow condenser is a must. Make sure it says Parallel flow not 6mm or Picco design.

R4 never has been a good compressor. Get either the replacement scroll or upgrade to a Sanden. Versions of both are made to replace the R4 and reuse the R4 style lines.

Use a cycling switch for your year truck meant for R134a. Also upgrade to a high pressure cut-off switch.

Flush everything and replace the orifice tube. I am using a variable orifice tube on my 97 Express and it seems to work a bit better than the standard one did.

Then get a better engine fan. The 5 bladed ones do not move enough air. The 11 bladed fan for a 99 Tahoe is a direct bolt on to a TBI.

R152a gives better vent temps than R134a. My center vent sits at 38F at idle in 105F.

 

[Jeepwalker]

Thanks for the info, guys ...and encouraging me to buy a new condenser rather than a salvage yard unit. That's what I did ....I ordered a Spectra 7-4168. They're not that much, and a direct fit for my 89 K1500. I called Spectra tech support to ensure it *is* a parallel flow, micro-channel unit (it is, or at least that's what the tech guy indicated). We'll see when it arrives. I also ordered a new hose kit, oil and a couple other doo-dads.

I'll remove ...drain & flush all the components and start over with new oil since I don't know what the previous outfit put in it after they flushed it, or what, if any, left-over mineral oil might be in the system.

Thanks for now... I may have more Q's later on.

 

[PlayingWithTBI]

That's what I did ....I ordered a Spectra 7-4168.

That's what I have in my 88 and, yes, it's a parallel flow condenser.