The TXV was sitting on my doorstep when I got home from work. It was around 80°, so I wanted to get it swapped and start the vacuum.
Of course there's always an issue and it started as a leak when the port valves were closed. I go to tighten the 5mm bolts and one strips the hole.
I run around to a few stores looking for a Heli-coil and of course nobody stocks one that small. I go to Home Depot and find that 10-32 thread pitch is a near perfect match. Apparently the stock bolts don't go all the way through the backing clamp, and I'm able to catch a few threads but I still use a lock washer and nut. Not the worst glitch; I'll get another clamp the next time I'm at the junkyard.
The system ends up holding vacuum for an hour after vacuuming for an hour. I also heated the drier for good measure. This drier has been exposed to air for at least an hour, over the last few troubleshooting sessions.
Time to charge. Charged as a liquid through the high side under vacuum and the pressures are at 22/100 with the first can and I'm already feeling cold air. It's already higher than last time with a near full charge. The second can takes me to 32/180 and I still need to add 5oz.
After adding 27 oz total, I'm seeing 55° at the vents on max/recirculate. Pressures are at 32/185. Wondering if this is anything like propane I take it to 1,750 rpm and only see around 50° with a 72° ambient. It's not propane cold, but this point, I'm not complaining! I figure if it's at least as good as 134a, I'll be happy for now.
So onto my new alternate refrigerant.... computer duster aka R152a.
Where I first read about it:
http://www.rx7club.com/2nd-generati...sy-cheap-safe-alternative-refrigerant-964688/
MSDS of the product that I used... take note of the manufacturer:
http://www.sisweb.com/referenc/msds/dustoff.pdf
GM/Delphi tests. Plenty more of these online:
http://www.sae.org/events/aars/2002/baker.pdf
I bought a 6 pack of "Dust Off" from Costco for under $20. Using the conversion, I needed 27 oz of 152a compared to 42 oz of 134a. $20 gets me almost 3 full charges. I figured if it didn't work out, I'd just huff the stuff. That's what all he cool kids are doing!
At this point, I'm claiming sucess and will be celebrating with beer and whiskey. Now, I just need my China compressor to hold up. If this goes well, I may upgrade to a large parallel flow condenser, later on.
-Todd