924Board.org

[CalGuy]

Hi Everyone,

I found out today from my A/C guy that the two refrigerant lines that go from the a/c compressor and desiccator to the evaporator inside the car are leaking. He said the leaks on these two hoses are small but probably enough for me to have lost most of the freon (it's only holding about 30psi currently). I think the last time I refilled the system was maybe two years ago (Jan 2017) or longer I can't quite remember.

I have a couple questions:

Are these two lines difficult to replace? I'm thinking it's a dash out job as both lines go through the firewall right about where the brake booster is located and connect to the evaporator which is right underneath the center speaker.

Has anyone tried a stop leak additive that worked for them? My AC friend says he hesitate's offering that as a solution since he has seen some compressors cease from it. My compressor is completely fine, no leaks and works great. Also he's not too sure which R12 stop leak additive's are fairly "reputable". I'm keeping the 924 at R12 mainly because changing to R134 would mean the system would run at a much higher pressure potentially making the leak worst.

Honestly, I'm leaning towards using a stop-leak product, if there is a good one out there that other's have used for leaks on their ac refrigerant hosees with success and recharge the system as opposed to changing the two hoses.

Thanks guys, any help is greatly appreciated!


_________________
-CalGuy
1980 924
1992 968 (Newest edition dubbed 1BAD968)
2001 Range Rover HSE

[Ozzie]

Personally wouldnt use them.
There is a sealant you can use on the hose ends when fitting but that is all i have ever used.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

[CalGuy]

Thanks Ozzie

What's the name of the spray?
_________________
-CalGuy
1980 924
1992 968 (Newest edition dubbed 1BAD968)
2001 Range Rover HSE

[Ozzie]

its not a spray its a thick gel which you put on the mating surfaces when assembling much like a thick loctite.
You would have to disconnect the hoses, put it on the surfaces and reassemble.
Cant remember the name and probably called different in your country
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

[CalGuy]

Thanks Ozzie for the clarification. I'll see what I can find based on that description.
_________________
-CalGuy
1980 924
1992 968 (Newest edition dubbed 1BAD968)
2001 Range Rover HSE

[PaulD_944S2]

Surprising that the evaporator lines are leaking, but anything is possible. Usually it is the front compressor seal that wears and leaks.

1. Don't use any kind of leak stopping additive, the fix likely won't be permanent and it will cost you more to make correct repairs.

2. The only "sealant" needed on hose connectors is the correct "O" ring and a light coating of compressor oil.

3. Convert your system to R-134A. The conversion is relatively inexpensive and since you are having to open the AC system, now is the time to convert. Vapor pressures for R-134A are very close to R-12, so don't worry about higher pressures. 924/944 condensers work well with R-134A. Make sure your radiator cooling fans work correctly.

To convert to R-134A, remove, drain, and refill the compressor with correct amount of POE oil, or replace compressor and drain/refill with POE oil. Replace the receiver drier with new, and add the correct amount of POE oil to the receiver/drier. Install the correct fittings, leave the pressure switches alone. Replace all "O" rings that are on hoses, you can replace the ones on the evaporator if you want to really dig in.

Porsche's conversion instructions:
http://www.944time.com/porsche/2005images/944_ac.pdf

Use an AC flush to clear out the mineral oil in the condensor and lines if you want, but POE is compatible with mineral oil in an R-12 system and if you have replaced the oil in the compressor and installed a new receiver/drier then you have removed most of the mineral oil.

POE/Mineral oil compatibilty:
http://emersonclimate.custhelp.com/app/answers/detail/a_id/980/~/mixing-of-polyol-ester-and-mineral-oil

Further, if you have to service the system, or refill every couple of years, the refrigerant cost will be much lower with R-134A, and with much less ecological and financial (to you) impact.

Good source of quality AC parts is (no affiliation):

https://griffiths.com/porsche/air-conditioning/924-944-951-968/

Good luck with your conversion, summer is coming!

[ted von Kampen]

I was reading your string on the leakage of Freon. As part of a rebuild and restoration of my 924 I rebuilt compressor and converted to R134. Over the course of a year I had to recharge several times because it would leak down. Finally I bought a cheap freon sniffer off ebay and started checking for leakage. To make a long story short I traced my leak to the conversion fittings that came with the kit. Schrader valves and O rings were leaking slowly. Last recharge was last fall and car has been in storage but when I check a week ago the AC still ran. So cold outside it is tough to test but thought I would pass my experiences along.