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I am sure I will be hitting you up for advice as I go. Did you know you wanted to go full monty from the outset or ?
It started as “clean the evaporator” and snowballed from there. The usual “if I’m doing X I may as well do Y and Z while I’m in there”. I had done the blower motors in 2018 I think. Regarding the soft lines, my thought process was that it would make good sense to change out the old R12 hoses for R134a/R1234yf-compatible hoses to avoid gradual leaks and refilling. My evaporator was pretty plugged, especially when compared to a new one. Condenser is the R134-style serpentine versus the tube-and-fin R12-style. Basically I wanted to maximize efficiency. Pressure switch is the original style so no wiring modification was required (OE made-in-Japan Denso part).
my car had 7/16 high and low so that should work but i'm not familiar with the brand and there is a difference, these ports can leak. I also replace the valve cores of the original schraders when I do this. have extras of those too btw.
Thanks. Will be needing a full set to convert. Issue with these air cooled cars is that AC was never that efficient to begin with. Your AC system will only be as robust as the most inefficient part. Evaporator seems to be the weak link from my understanding.
Ok lets get to it. I have some r134a some ester oil with dye and new o rings. I emptied the compressor as best I could. Tested the clutch. I am not entirely certain how much ester to add. Porsche specs below.
I used the Griffiths kit. I replaced the evaporator, condenser and dryer. I kept the hoses and compressor and refreshed all the o rings. The case split isn’t hard, it was the removal and reinstallation that tested my patience most.
Stupidly I didn’t take many pics of the split case.
The only split case photo I have and it’s terrible. Lots of others of the process though if you need anything.
I cleaned the old compressor of oil as best I could and assembled it dry. Presently pulling a vacuum for an hour then will add 1oz Ester+UV, charge to 840g R134a and plan to run only long enough to check for leaks. I will then plan on getting a flush gun to clean out any components I'm not replacing.
haven't decided which components to replace yet but was happy to see OEM / German options not crazy expensive. I realize there are upgraded options, at a cost, and yet unsure if I'll spring for them.
Exciting to know that you have the tools to do this job!
My thought would be to spend up for the improved griffiths evaporator, just because it's such a hard piece to access. The other stuff is easier to replace.
I have this job to look forward to. My 1990 C4 is still on R12 and I want to refurbish the whole system to R134s. So keep documenting what you are doing. I want to figure out the best bang for my buck solution.
I will document the process but make no promises for results. I have built four motors and all turned into strong dry runners but A/C has defeated me... badly...
Hoping to turn over a new leaf.
one mistake I know I made already was ordering "straight" R134a adapters. No way the high side quick connect will fit against the oil filter once the adapter is installed. Will need a 90 deg fitting...or... per my photo it is possible to simply remove the quick disconnects from the R134a manifold set and thread them directly onto the R12 fittings. I have been told (and know from experience) that you are supposed to have a "low loss" or some such fitting so that high pressure refrigerant doesn't squirt out while you're removing the fitting.
Okay now down to the garage to see if vacuum held... its been 2+ hours.
But i know what will happen. I'll drive around all summer with the windows open. And another six years will go by, and I'll need another refill....
here in Northern California I think the best option is “do nothing” and just make sure my servo motors are working.
EDIT: finally found an A/C delete thread. Removing my compressor, the big A/C bracket, and then removing and closing up the two A/C lines. I see you just remove the left rear fender liner and the hoses are easy to get to and remove. https://rennlist.com/forums/964-foru...-c-delete.html
Vacuum held at ~30in which means no gross leaks but certainly is not a final test.
This means time to charge her up. This is not as simple as it sounds without a big cylinder (note: not opposed to group buying a big cylinder). The little cylinders have to fight against the pressure in the system and need some coaxing to release their charge. I cycle between cylinders, letting each of them sit near the engine to heat up in between. You have the weigh them before and after to tell exactly how much you have charged the system. I'd say I got it pretty close to factory spec...
Nice to see the compressor cycle on as the pressure built up and make no untoward sounds in the process...
Cabin is cold which means approximately nothing since Connecticut is cold. Looks like Tuesday will see some rising temps and a chance to test the system, see if the pressure holds.
04-24-2020, 12:27 PM
I had done the blower motors in 2018 I think. Regarding the soft lines, my thought process was that it would make good sense to change out the old R12 hoses for R134a/R1234yf-compatible hoses to avoid gradual leaks and refilling. My evaporator was pretty plugged, especially when compared to a new one. Condenser is the R134-style serpentine versus the tube-and-fin R12-style. Basically I wanted to maximize efficiency. Pressure switch is the original style so no wiring modification was required (OE made-in-Japan Denso part).
