AC compressor replacement.

[FrankieD61]

What do I need to do this correctly? My ac compressor locked up over the winter while I had my defrosters running. I'm looking to replace it. I don't the the truck has has a properly working ac system in quite some time...

 

[smdk2500]

Parts wise Compressor, drier, orifice tube possibly new condenser, o-rings oil and flush kit. Some places sell all these as as one kit.
Tool wise all the stuff to take the parts off. I don't remember what all you need but its just standard hand tools. You will need to vacuum the system down after you replace the parts. So will need a vacuum pump and gauges. Some people will do all the work and then take it to a shop and have them vacuum and charge due to cost of the equipment.

 

[1998_K1500_Sub]

This topic was covered in a lot of detail here, with MANY posts, for a guy who had similar AC problems although with a factory R134a system.

1996 C1500 Reg Cab AC not working - what all do I need?

Hi, I have a 1996 C1500 4.3 reg cab 8ft bed and the A/C is not working, just blows ambient air. Is there anything simple I might be able to check to see if the system is salvagable? I was thinking if the system is bad, to maybe buy a kit or the individual parts needed to replace and flush...

www.gmt400.com

Since yours is a 1991, it was R12 at one time and I assume converted to R134a. That's a bit different can of worms, since the condition of your system is likely "It's been converted and I don't know much about it". We can cross that bridge later. Much of what @smdk2500 said, jibes.

A good R134a conversion would necessitate other things which may or may not have been done, prior.

Tell us more about its history.

 

[FrankieD61]

Tell us more about its history.

That is still in the works... Winter in the good old state of NY makes things a little tough... I'll be sure to let you guys know what I find out. I'll also read of that thread you shared.

Thanks.

 

[1998_K1500_Sub]

Here's another recent thread that's on-going, dealing with an older R12-converted-to-R134 system that the owner's having some problem with, now:

AC compressor port on back left? Leaking from snap ring - what is it?

I found a leak on my compressor. This port off the back side of the compressor itself is slowly hissing. The compressor works and keeps the interior cool but that port leaks down to the point where the clutch won't lock anymore. Can I reseal what is there? It looks like a snap ring holding...

www.gmt400.com

Might not be directly related but still interesting reading.

 

[Eveready]

If you have the time and expertise go for it. After fighting this battle for two seasons I fired the money cannon at mine and just had it fixed. It cost more than it is worth and maybe more than the truck is worth but here in the South AC is a necessity.
I can keep it charged,pump it down and do other service, but I start with a working unit and it was worth it the first day over 90 degrees!

 

[1998_K1500_Sub]

If you have the time and expertise go for it. I fired the money cannon at mine and just had it fixed.

So true... the parts aren't really expensive, maybe $500 for a new Sanden compressor, condenser and receiver / dryer, less for other compressor makes. It's IMHO mostly a level-of-experience / confidence hurdle, not a financial one.

(a Sanden retrofit is a bigger job when replacing an R4 compressor, as brackets and hoses are required; Sanden's drop-in retrofit is only available with their p/n 4440 or p/n 4261 replacements for the HT6 compressor used on GMT400s 1996+)

 

[Schurkey]

What do I need to do this correctly? My ac compressor locked up

Your COMPRESSOR locked-up?

Or your compressor pulley BEARING locked-up?

There's a potential difference in repair process. If the compressor locked-up, you will need to solvent-flush EVERYTHING, and replace the orifice tube and dryer, there will be shrapnel everywhere in the system.

If the bearing locked-up, you need (at minimum) a new bearing. No big deal. If the system held pressure, you wouldn't even need a re-charge. The issue would be whether the system held pressure.

Naturally, you'll need to leak-test every joint/seal, and all the individual parts. In general, there's more problem with the condenser leaking than the evaporator, but both are suspect until proven good.

Given a choice, I'd want a new orifice tube and dryer no matter what. That's based on the age of the truck. If the system wasn't holding pressure, I'd replace every O-ring on general principles.

I put a compressor, orifice tube, dryer,and O-ring kit into my Trailblazer. Every "special" tool I needed was available from the Loaner-Tool program at O'Reillys. Other parts stores have loaner-tools, too.

 

[FrankieD61]

Your COMPRESSOR locked-up?

Or your compressor pulley BEARING locked-up?

As soon as the clutch engages, the belt squeals and slips like a SOB.

 

[Schurkey]

Yeah...that's the expensive one.