1955 Air Conditioning, correct refrigerant?

[Texas TBird]

My 1955 Tbird AC died over the winter. I want to add coolant to see if that's the problem. My SD507 Sanden compressor calls for R12. I found R12 or equilivent on Ebay, but want to make sure it's the right stuff. There's a blue cover on my compressor and I was wondering if that's a sign that the unit has been updated to R134. Any advice or ideas of how to proceed? Is my AC original or an aftermarket?

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[biddle]

Title "1955 Air Conditioning" has been revised to reflect exactly what your post is about.

 

[biddle]

Per Google:
The Sanden SD507 (also known as SD5H11) is a popular, compact 5-cylinder aftermarket A/C compressor, often used in hot rods, custom cars, and heavy-duty equipment. It features modern rotary internals for reduced noise/vibration, supports R-12 or R-134a refrigerants, and generally comes with a 2-groove V-belt clutch. [1, 2, 3]
Key Features and Specifications:

• Design: Ultra-compact, lightweight, often with "ear-type" mounting on all four corners for versatile installation.
• Performance: 108CC ($6.59 \text{ CID}$) displacement, suitable for various aftermarket systems.
• Clutch: 2-groove V-belt pulley (typically $125 \text{ mm}$ or $132 \text{ mm}$).
• Port Type: Vertical top O-ring ports.
• Voltage: Commonly 12V (24V versions are also available).
• Oil Type: Usually requires PAG 100.
• Popularity: A common upgrade or replacement due to its smaller size compared to the Sanden SD508, making it ideal for tight engine compartments. [1, 2, 3, 4, 5, 6]

Compatibility:

• Refrigerant: Compatible with both R-12 and R-134a.
• Application: Frequently used in vintage air conditioning kits, tractors, excavators, and hot rods.
• Interchangeable Models: SD507 / SD5H11. [2, 3]

It is highly recommended to verify the specific mounting style (ear type), port configuration, and clutch pulley groove count against your previous unit to ensure proper fitment. [6]

AI can make mistakes, so double-check responses

[1] https://www.oerparts.com/product/ac5104n.html
[2] https://www.classicindustries.com/product/ac5104p.html
[3] https://www.amazon.com/sanden-sd507/s?k=sanden+sd507&tag=thunderbirdforum-20
[4] https://m.intl2008.com/products/a-c-compressor-sanden-sd507-9173-universal.htm
[5] https://www.vividracing.com/four-se...507-compressor-wclutch-58567-p-154302828.html
[6] https://www.ebay.com/itm/1873666532...pid=5338236430&customid=&toolid=10001&mkevt=1

 

[Tom Alpers]

The fact that is has the blue and black caps is almost certainly indicating its using 134a. The unit you have inside looks like the "modern" ones that have been used for a while. While that system/conversion, may have been done a while ago it was probably done after R12 was phased out which was in the early 90's, which, hard to believe, was about 35 years ago!!! It looks pretty much like my system, which I put on 3 years ago. When evacuated/empty they only take about 1 can of 134a.

As to whether its original or aftermarket.... They never had any AC option when these cars were new. They did add it aftermarket back in the day but way back then the compressors were the large square "York" style and many of the under dash units were large and ugly looking until Mark IV and similar style units hit the market in the 60's. They looked very similar to what you have.