AC Compressor doesn't engage

[roostabunny]

Yep, evac first. No reason you can't use a bolt with the correct thread and length, I'd use some thread sealer like Permatex #54540 on it.

Wanted to wrap up this thread. Again, in the "life happens" category, got distracted by getting windows working, a birf rebuild, buying our first house and having more opportunity to finally get rebuilding on my motorcycle engine. All awesome things. I mean, I have a garage! No more working in the parking lot and having to unpack/pack tools etc and make it look good so we don't get evicted.

So, fast forward multiple summers... and my AC is now working great.

Where I left off was buying the M8 bolt and that's been sitting around in a box labeled 'Vera AC' with a replacement receiver/dryer and an assortment of green orings for years. A few weeks ago I finally trimmed the bolt down to length, cleaned up the threads, applied some thead seal, put on an oring, and threaded it in. Then I borrowed a vacuum pump and gauges.

I pulled a vacuum on the system for about 45 minutes, and was disappointed when it seemed to loose vacuum pretty quickly - visible movement of the needle after only about 20 minutes. I thought I needed to find a leak, so I added some dye and enough 134A to get the compressor moving. My low pressure valve hissed for a bit after I removed the gauge, then stopped, but with only a bit of refrigerant, cooling was not impressive. Then a friend mentioned that after all this time and a leaky system, I might actually need to have a vacuum on the system for way longer than 45 minutes to get all the water out. Meanwhile, water would continue to evap, reducing the vacuum. So, after a few days the I depressurized the system and hooked it up again. I saw a reassuring puff of condensed water vapor when I first fired up the vacuum pump, and left it for several hours.

Vacuum held much better after that, so I swapped in new valve cores just to be safe, swapped in the new r/d, and vacuumed it down again for about an hour (should be OK, given the long pull before and that most of the moisture would have been coming from the old r/d anyway).

Vacuum still held well, so I measured out .7 oz of 134A-compliant compressor oil (amount per the FSM for a r/d) that was pre-mixed with some leak dye just in case, poured that in the middle hose, hooked up my first can of 134A, and fired up the truck. It drew the refrigerant in and the compressor kicked in shortly. Added about 32oz, I think, using the very inaccurate fish scale (picked up at a yard sale for birf jobs) to guesstimate the last partial can.

Was now blowing <50°F at the vents in over 90°F ambient, so I was thrilled. I closed up the gauges and removed and was horrified to hear hissing from the low pressure fitting again, but quickly grabbed the valve tool and figured out that I hadn't snugged the valve up the whole way. Hissing stopped, checked the high side valve again for good measure, then threaded on the caps.

Over a month later, I'm still still getting between 40-50°F in the hottest part of a truly hot Alabama summer, and my girls no longer mind riding with Daddy in the heat, which is the best part. Thanks, @1972FJ55 and everyone! Ask questions if you got any.