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

[Schurkey]

What can-tap are you using?

US EPA regulations changed the thread-on "Pounder" refrigerant cans (typically 12 oz net weight) so that thread-on can taps for the older cans won't work on the "Self-Sealing" newer cans. I got caught on that when I was working on the Trailblazer A/C. Had to order a new can-tap from Amazon.

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But of course there's many suppliers of essentially the same thing.

If you're not using the "one-pound" "Pounder" cans, or you're not using thread-on can taps, I don't know what's going on. Do your AC manifold gauge hoses have in-line shutoff valves? Mine do. Did you open those valves?

 

[Stringer]

What can-tap are you using?

US EPA regulations changed the thread-on "Pounder" refrigerant cans (typically 12 oz net weight) so that thread-on can taps for the older cans won't work on the "Self-Sealing" newer cans. I got caught on that when I was working on the Trailblazer A/C. Had to order a new can-tap from Amazon.

xc_hide_links_from_guests_guests_error_hide_media

But of course there's many suppliers of essentially the same thing.

If you're not using the "one-pound" "Pounder" cans, or you're not using thread-on can taps, I don't know what's going on. Do your AC manifold gauge hoses have in-line shutoff valves? Mine do. Did you open those valves?

ive got the supertech 12 oz cans from WM

i dont know about inline shutoff valves. i did open the low valve to try to get refrigerant to go in. i have this manifold set and the can tap that came with it. GAUGES

does that look like a can tap that wont work?

 

[AuroraGirl]

Pull that snap ring out on the new compressor, at the center, then the plug (BTW, vent the compressor first by loosening the port cap on top slowly, as it may be pressurized).

Do the same on the old compressor to remove the switch.

Clean the dirt and crap from the switch / body, and install with new O-ring (smudged with Nylog) in new compressor.

Or, install a new switch if you have one. I simply re-used mine, which might be poor procedure but it's what I did. That switch doesn't see much use and in my case was likely in a closed state its entire life.

Is this an R134a compressor its going from and to? I didnt know if the compressor in question originates on the truck or not, figured to ask.

6.6 oz is 7.1 if you squint enough

 

[AuroraGirl]

ive got the supertech 12 oz cans from WM

i dont know about inline shutoff valves. i did open the low valve to try to get refrigerant to go in. i have this manifold set and the can tap that came with it. GAUGES

does that look like a can tap that wont work?

I had to get different can tap when I bought my cans locally instead of from online. It used a plastic collar thing instead of just onto the center of the can. So I have both

I also had to use an adapter from the yellow fill hose thing, but my set is r22/r134a so I suspect the wrongthread thing was correct for r22 use maybe

 

[Schurkey]

ive got the supertech 12 oz cans from WM

Where you buy them shouldn't matter. WHEN you bought them might.

A year ago, I could find a couple of old-stock, old-style cans of R134A. Virtually everything on the shelf was the new design, "Self Sealing" or "EPA Approved" wording printed on the can.

i dont know about inline shutoff valves. i did open the low valve to try to get refrigerant to go in.

I don't see obvious in-line valves. There may be valves in there, though. Do you see Schrader-valve stems in the hoses? (not just Schrader-valve depressors)

Some manifold gauge sets have ball-valves near the free-ends of the three hoses.

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i have this manifold set and the can tap that came with it. GAUGES

does that look like a can tap that wont work?

There's a Schrader valve in the threaded neck at the top of the new, "Self Sealing" Pounder refrigerant can. Used to be, it was just stamped metal, the can tap would puncture the can. Now instead of a sharp "needle" to puncture the steel, there's a blunt "needle" or "plunger" that just depresses the Schrader valve. When you unscrew the can-tap, the Schrader valve re-seals the can so the refrigerant inside doesn't escape.

If your can tap has a SHARP point that screws down in the middle of the threaded part, it's not going to work on the new cans. You need a can-tap with a BLUNT plunger.

I had to get different can tap when I bought my cans locally instead of from online. It used a plastic collar thing instead of just onto the center of the can. So I have both

Your can tap punctures the side of the can, instead of threading onto the nipple at the top of the can? I have one of those for R12 pounders. Can't be used on R134A pounders due to the different size/shape of the can.

Mine is the older, blue-plastic version sorta-like this one. If I didn't use all the refrigerant in the can, I had to leave the tap clamped onto it, because the punctured hole in the side of the can would just allow the unused refrigerant to blow out. But leaving the tool clamped on the can is hard on the black-rubber seal which distorts, and eventually cracks and leaks. I did find a source for the black-rubber seals, though. IIRC, Mastercool sold 'em.

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I also had to use an adapter from the yellow fill hose thing, but my set is r22/r134a so I suspect the wrongthread thing was correct for r22 use maybe

Seems reasonable.

 

[1998_K1500_Sub]

does that look like a can tap that wont work?

That can tap looks like the ones we used to use on R12. I haven’t seen any like that used on R134A.

@Schurkey has given you good information.

I think you will be better off if you charge with liquid first and then switch to vapor; the process is a little more involved, but it goes a lot faster and it helps circulate oil to the compressor sooner, which IMHO is important with a new system like you’re putting together.

Don’t just jump into this… It’s something you need to think about completely before doing.

And I don’t recommend you jumper around the low pressure switch to force the compressor to run so that you can charge through the low pressure side. Why? You’re spinning the compressor a long time but there’s no oil flow through the system because it’s not circulating refrigerant.

 

[1998_K1500_Sub]

I really believe you should just leave vacuum on it all night. There’s no harm in it, if the vacuum drops off it tells you you might have a problem, and it gives you time to think longer about what your next step is going to be.

But it already looks like you’re trying to charge it…

 

[AuroraGirl]

Where you buy them shouldn't matter. WHEN you bought them might.

A year ago, I could find a couple of old-stock, old-style cans of R134A. Virtually everything on the shelf was the new design, "Self Sealing" or "EPA Approved" wording printed on the can.


I don't see obvious in-line valves. There may be valves in there, though. Do you see Schrader-valve stems in the hoses? (not just Schrader-valve depressors)

Some manifold gauge sets have ball-valves near the free-ends of the three hoses.

You must be registered for see images attach

There's a Schrader valve in the threaded neck at the top of the new, "Self Sealing" Pounder refrigerant can. Used to be, it was just stamped metal, the can tap would puncture the can. Now instead of a sharp "needle" to puncture the steel, there's a blunt "needle" or "plunger" that just depresses the Schrader valve. When you unscrew the can-tap, the Schrader valve re-seals the can so the refrigerant inside doesn't escape.

If your can tap has a SHARP point that screws down in the middle of the threaded part, it's not going to work on the new cans. You need a can-tap with a BLUNT plunger.

Your can tap punctures the side of the can, instead of threading onto the nipple at the top of the can? I have one of those for R12 pounders. Can't be used on R134A pounders due to the different size/shape of the can.

Mine is the older, blue-plastic version sorta-like this one. If I didn't use all the refrigerant in the can, I had to leave the tap clamped onto it, because the punctured hole in the side of the can would just allow the unused refrigerant to blow out. But leaving the tool clamped on the can is hard on the black-rubber seal which distorts, and eventually cracks and leaks. I did find a source for the black-rubber seals, though. IIRC, Mastercool sold 'em.

You must be registered for see images attach

Seems reasonable.

oH NO my bad The plastic collar was on the top, kinda like a butterfly valve for an old propane tank or a faucet but plastic and its how you secured the tap to the can. probably to aid in removal and install. The older style tap was just a puncture thing like you said.

I found the new self sealing cans dont seal all that well.. so I left the can last used on the yellow hosewith my gauges because i didnt want the drama of going to use the can and its empty anyway lol. Still holding. Maybe it was a cheap brand or cheap tap.


The "when" must have been the case, I bought these back in 2020 when I learned how to charge AC. I charged my cars AC 3 times before deciding to pull the components from the car for access to stuff(I could live without, the bearing on compressor was starting to get noisy and last I needed was that seizing. it was oem 225k ish miles.

The V5 compressor was so ******* packed with UV dye and oil I dont know how the thing ran or blew so cold. I had removed each line to them all oozing so much oil and dye. Evidently the PO did what I did but used those **** "all in one" cans with no gauges. I only added pure refrigerant and pulled vacuum(the first time) I just added the last 2 since it was still charged, only vacuumed the lines and then purged before opening to the system.

Still have the compressor since fun conversation piece and its still slowly oozing out everytime Its shifted or the temp changes lol...

for fun this is what I had gotten its more pricy now:

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ramble:

But the car had something wacky and thats the AC pressure sensor thats on the pipe with the muffler(compressor muffler) is not connected to anything and the scan tool reads live data when running. IF I unplug the sensor, same story (rip)

Its on its own 5v reference from the PCM. I just wish I knew whether the PCM a & b 5v ref can pull eachother high or low. I am asuming not but its not a very common issue lmao

With out a compressor, AC relays or fuses, and the wiring harness opened up quite a bit far back I cant figure out where its getting small voltage but I figured my OE alternator should get replaced because the bearing is slightly noisy and I may find out its some emi(since the alternator has 2 of 4 wires going to the pcm for energizing and monitoring, using a duty cycle who knows) or if the PCM is on its way

Crazy times

 

[AuroraGirl]

ive got the supertech 12 oz cans from WM

i dont know about inline shutoff valves. i did open the low valve to try to get refrigerant to go in. i have this manifold set and the can tap that came with it. GAUGES

does that look like a can tap that wont work?

That may be for a R1234YF possibly? That ******** is the new and eventually nonsense thats going to be forced into all new cars. It would be so bad if (honeywell? Dow?) DIDNT HAVE EXCLUSIVE PATENT RIGHTS TO IT.

The amount for so little is so much. And the systems run a lot higher pressures to use a less efficient refrigerant thats a racketeering operation but different because its done by a company. So its called "planet friendly"

Id rather use propane or whatever the weird kid is huffing from officemax as replacement than ever pay for that armed robbery disguised as eco.
So what if its flammable they already tell me im basically dead in any accident since I dont drive a 2023 model year car. (they being people. same ones who buy AWD for "The snow" but never put anything but a all season on it)

 

[Stringer]

Thanks to all for this help!! Clearly I was in a little over my head here, though that is kinda how i force myself to learn new things sometimes. Not exactly a textbook perfect install procedure (my fault of course), but thankfully I think things worked out well.

I got a new can tap from oreillys which then required a 1/2" ACME to 1/4 flare adapter, luckily i had this.

vacuumed out the system and started from scratch with new tap, worked great. used a scale to measure can so i know i got just the right amount of refrigerant in there.

after about 20oz the compressor no longer cycled on-off intermittently and stayed on which is great.

i dont have a dial thermometer but it is blowing cold af.