Complete new A/C system problem? Help!!

It's easier to add later than take away, so I'd start with 32oz and then if the temp delta isn't sufficient, add a few more.
Isn’t there a sticker under the hood with the exact amount?
It's usually on the accumulator/dryer on those body style of trucks and once that is replaced, it's gone. At least that is where it was on my 98 K1500 and on the 97 K1500 farm truck when they had their original accumulators.
Well guys, are ya still here?? This saga ain't over...

So finally this evening I got my gauge set repaired. I vacuumed down the system for 1 hour plus like I usually do,, and all good. Shut down the vacuum, and the system held for 30 minutes - no leaks.

Feeling pretty good at this point...

Then I started charging the system, or trying to... With freon hooked up, when I opened the low side valve a little, the low side gauge went from vacuum to about 80 psi or so. High side was just over 125 psi. But that was it. Period. It never drew in the freon. I fought with it for about 30 minutes, then quit as I was worried about damaging the new compressor due to lack of flow. The low side connection felt cool, (not cold) to the touch, and the high side quite hot. Unlike normal, I had to jump the low pressure switch to get the compressor to kick in. Usually, the vacuum draws in enough freon that the compressor kicks in and I don't have to jump the low pressure switch, but not this time.

What do you guys think?? My only guess is that 450 psi of reverse pressure from when I had the lines reversed seriously damaged the orifice tube and now it doesn't want to flow.

Why is it that hundreds and hundreds of my customer jobs go just fine, but when working on my own stuff, things go to crap!!??

I'm so bummed right now. I've had two serious back surgeries and I'm now due for a third, so I'm trying to get all this done while enduring intense pain.

Ideas guys??

Vettepilot. :~(
Man, you called it!! Well, sort of... Your comment caused me to check all my lines, as I recently swapped them. I had changed some totally worn out lines for some much better looking, but still old lines, to use while waiting for my much needed new gauge set to arrive. All the connections were good except one. One of the low side hose ends had the rubber gasket completely covering the holes, not allowing flow.

I changed that line and have since used the set to service another vehicle just fine, so I know that gauge set now works, and will be my backup set. The new gauge set arrived, and I will use it to fill the "problem truck" tomorrow. Hopefully that's all that was wrong and it will work fine, as fixing this particular truck up has been beating me to death.


Ok guys. After the hose switch-up on my truck, I decided my gauge hoses were too old to use anymore, so I switched them out for a backup set I had. Turns out, the blue hose on that "backup" set had a blockage. The sealing washer was covering the outlet holes.

All fixed now, and A/C blows 37 degrees!!

  • Helpful
Reactions: D60