Broken A/C troubleshooting

[BennSport]

Just tried contacting several hvac services and they could due to needing special automotive licenses. Later today I’ll inquire online about some local garages that might offer r12 evac.

[blueline]

Tried any of these?

A-Gas (Rapid Recovery Salt Lake City) 801-364-6600. Big company. They buy used refrigerants too.
https://www.agas.com/us/products-servic ... lake-city/

Steve's Automotive Specialists 801-466-2886
Liberty Auto Repair, LLC 801-581-0114
Craig's Service Center 801-581-0114

[BennSport]

Yea, I called all of those shops this morning and they all said something along the lines of “we don’t have a machine for R12”

[BennSport]

Out of curiosity I ended up purging the high side schrader valve to see how much was in there. It ended up spraying gas out for like 3 seconds and then it stopped so I assume there was so little r12 in the system and it’s cleared now. Moving forward with the conversion I’ve been following NC944ER’s video, and I was wondering if there are any o-rings to replace by the condenser and evaporator assembly? Also since I’m reusing my old compressor should I replace the o rings that go between the compressor and the top plate?

[Tom]

Good work! While technically not permitted, as a practical matter that amount of r12 would have leaked out on its own, just like the other 30 oz that already did. Yes, re the o-rings. See the parts diagram I posted above. The ones at the condenser and compressor are relatively easy, and necessary if you update the hoses to r134a barrier hoses. The one at the firewall are a pain I've avoided unless/until they actually leak. Change the easy ones, pull a vacuum, and cross your fingers it hold full vacuum for an hour+.

If you have not discovered it already, Porsche has its full parts diagrams (aka PET) online for these cars. If you get the part number in PET, you can shop around online for the best prices and shipping options.


https://assets-v2.porsche.com/us/-/medi ... 88_KATALOG

[BennSport]

Would replacing the barrier hoses be 100% necessary? My kit gets here today, and I was planning on hooking up the high side fitting to the vacuum pump and doing a leak down test before I start any work on the system. I figured if the barrier hoses were leaking then I’d swap them, but as they’re expensive I’d rather not if I don’t have to. Since my low side 90 degree fitting doesn’t arrive till next week will I still be able to perform a comprehensive leak down with only the high side hooked up to the pump?

[BennSport]

Also, examining my PET diagram I’m seeing 2 units (33 and 33A) that are both referred to as the “air conditioner” and I’m a little confused regarding that. The BOM list doesn’t even show a “33A” part

[Tom]

I forgot you have an early a/c system, but looks like you found the right PET. What year is your car? My comment about the o-rings being hard to get to on the evaporator were based on the later cars. Yours might be easier and worth changing. PET has a lot of translation quirks -- that part 33/33A appears to be the blower/evaporator housing on the early cars -- calling it the 'air conditioner' is probably a translation thing. And it looks like they missed listing the 33A parts, maybe because it was superseded?

Here's what Giffith's says about the hoses: "The original rubber a/c hose lines in your car will leak out R12 through the hose’s lining. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. So if you car has a large amount of rubber hose, such as a 40 feet with the 911, then you will be re-charging the system often and that is expensive no matter which refrigerant you use. To prevent refrigerant loss you should consider replacing your old hose lines with “barrier” type hose."

I changed the easy ones on my car, but still have some original non-barrier hose left. It's not an all or nothing thing. The less original hose you have, the less seepage (aka, leaks you don't feel like fixing as dr bob points out). And the less seepage, the less often you need to refill the refrigerant.

[BennSport]

My car is an ‘83. I’ll dig around to figure out the accessibility of the condenser/evaporator connection points. Since I’m still waiting on the low side fitting I have a couple days to assess what I want to do depending on if and how much the system leaks pulling vacuum today. I will probably proceed without replacing the hoses right now, but if it proves to be a problem I will just end up replacing them.

[BennSport]

Just received my conversion kit in the mail, and I’m wondering what these silver and white pieces are for on the right?