Double Doofus - Air conditioning on a 69 Fury III vert

3175375

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The factory R-12 system had about 12oz of oil installed in it. After repeated evacuations, you have lost a significant amount of oil due to evaporation. Secondly, anytime a receiver/dryer is replaced, it will have about 6oz of oil trapped in it. I would suggest adding at least 6oz of oil to compensate for this loss. If you can find a spec sheet for the replacement scroll compressor, it might have the amount of oil listed for the conversion process. Most modern scroll compressors have a 6oz minimum.

Dave
Thank you!

I will address this and discuss it with my cousin, taking your recommendations seriously.
 

3175375

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Installed receiver/drier and on @Davea Lux ’s recommendation of adding 6 oz of oil in the receiver, I have added ~4 oz.
I had previously added about 1 to 1-1/4 oz, and I think that I’ll be in the ballpark.
From what I have dug up, the R508 compressor takes about 135cc (4.75 oz), and from the seepage when I pulled the receiver/drier, I believe that I am good.

I installed the low pressure switch using the new oring and scraped off the paint and sticker from the sight glass.

Next: expansion valve, evacuate, charge and report back…

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3175375

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Replaced the expansion valve, Evacuated the system, charged it and it works!
When I recharged the system, verified that the sight glass was cleared (no bubbles).

Air conditioning compressor is on in all modes, will update the control switch post on updates.
 

John Kirby

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I redid mine a few years ago. Went to NAPA and got a couple cans of AC flush. Just stick the low pressure hose going to the compressor in a gallon milk jug. Blast the flush through the line coming from the receiver dryer.
Replace the exp valve and receiver dryer + a condenser would be a good idea too. Lots of places where old crud can hide in them. Nearly impossible to clean completely. The crud will look rather nasty when flushing. Keep
doing it until it looks clean. Don't skimp in this area. Buy the correct oil for the sanden compressor. There should be a label on the side specifying this. Once reassembled with new hoses, put a vacuum pump on the system
and let it run overnight. Then inject about 6 ounces of oil followed by freon. I wouldn't waste time or money on r12, switch to R134 and your wallet will be much happier. A 508 Sanden compressor can be found new on ebay
for less than $150. Haven't checked lately though. You really need to replace all the rubber hoses with new. But it looks like that has been done already. When filling with R-134 use the correct gauge set and use the temperature
scale to determine when it's full, set it around 40 degrees. Any lower and the evaporator can freeze up. After doing this you will find out what the next weak link in the chain is.

Wouldn't hurt to make sure the evap box under the dash is cleaned out of old leaves and other junk too.
 

3175375

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I redid mine a few years ago. Went to NAPA and got a couple cans of AC flush. Just stick the low pressure hose going to the compressor in a gallon milk jug. Blast the flush through the line coming from the receiver dryer.
Replace the exp valve and receiver dryer + a condenser would be a good idea too. Lots of places where old crud can hide in them. Nearly impossible to clean completely. The crud will look rather nasty when flushing. Keep
doing it until it looks clean. Don't skimp in this area. Buy the correct oil for the sanden compressor. There should be a label on the side specifying this. Once reassembled with new hoses, put a vacuum pump on the system
and let it run overnight. Then inject about 6 ounces of oil followed by freon. I wouldn't waste time or money on r12, switch to R134 and your wallet will be much happier. A 508 Sanden compressor can be found new on ebay
for less than $150. Haven't checked lately though. You really need to replace all the rubber hoses with new. But it looks like that has been done already. When filling with R-134 use the correct gauge set and use the temperature
scale to determine when it's full, set it around 40 degrees. Any lower and the evaporator can freeze up. After doing this you will find out what the next weak link in the chain is.

Wouldn't hurt to make sure the evap box under the dash is cleaned out of old leaves and other junk too.
Shamu had been ‘restored’ back in 2014. All components looked nice.
I know that the expansion valve was bad and replaced it along with the receiver/dryer. After quite a bit of work regarding the mode control switch, 3 vacuum actuators and plumbing, it’s now operating correctly. I have access to R-12 and chose to keep that.

Thank you for the comments and I agree with you that all of your suggestions are good.
 
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