Topic: AC Compressor

[rweis]

I have a question regarding prefix and date codes. I have a 1970 Mach 1 and trying to find out if the AC compressor is original to car. The car came out of the Dearborn plant in December of 1969. It has York compressor. I would have expected it to have C9 or D0 prefix but it has C8 prefix. However, the date code on the tag 079K.(October 7th, 1969) I it possible they would have put a C8 part on a 1970 model? Thanks

[Bob Gaines]

I have a question regarding prefix and date codes. I have a 1970 Mach 1 and trying to find out if the AC compressor is original to car. The car came out of the Dearborn plant in December of 1969. It has York compressor. I would have expected it to have C9 or D0 prefix but it has C8 prefix. However, the date code on the tag 079K.(October 7th, 1969) I it possible they would have put a C8 part on a 1970 model? Thanks

In the realm of anything is possible then I guess it is possible but in this case not very likely.

[rweis]

I also thought it was unlikely but the date code made me think twice. Thanks for your thoughts, it's greatly appreciated.

[hopey]

You are confusing part numbers with date codes. They didn not change the part number every year, only when there was a significant revision or a new part. You will have C5, C6, C7, C8, C9 and D0 prefixed part numbers on your 1970 Mustang. Maybe even earlier ones, Eg possibly your lug nuts.

[Bob Gaines]

You are confusing part numbers with date codes. They didn not change the part number every year, only when there was a significant revision or a new part. You will have C5, C6, C7, C8, C9 and D0 prefixed part numbers on your 1970 Mustang. Maybe even earlier ones, Eg possibly your lug nuts.

Engineering numbers(what I call them) that are found on the part are typically different then the part numbers that are used for inventory found in the MPC. The MPC will sometimes list the engineering number to identify the part also.In this case we are discussing what is typically found on the A/C compressor.

[rweis]

These are different engineering numbers for AC compressors that are interchangable and appear to be the same other than the prefix. C8AA-2875-A2, C9AA-2875-A2 & D0AA-2875-A2. So why would they use an AC compressor with a C8 prefix on a 1970 model when there are more recent prefixes for the same compressor? This is why I question whether it is the original compressor.

[J_Speegle]

Not sure if it was you that posted elsewhere about the label and color of the preprinted details - if they were originally red or black

Took the time to go through my pictures of 70 Dearborn cars and offer the following. Found no ones with black print




Unfortunately no close ups of the numbers or date on the 70 labels to help with the C9 or DO prefix

Only have earlier examples. Here is a label from a big block engine compartment kit for 69's boxed in 1969




And a few more labels from other applications and years

[J_Speegle]

These are different engineering numbers for AC compressors that are interchangable and appear to be the same other than the prefix. C8AA-2875-A2, C9AA-2875-A2 & D0AA-2875-A2. So why would they use an AC compressor with a C8 prefix on a 1970 model when there are more recent prefixes for the same compressor? This is why I question whether it is the original compressor.

Consider that any differences would be internal and not visible rather than ones that would affect the "look" of the compressors. Example would be ones built differently for high performance applications and possible higher rpms.

By you posting I guess yours has a visible label on it. Why not post a picture so we can see everything? Might help with the answer as to why a C8 is on a 1970 application

[Bob Gaines]

Something to keep in mind is the the vast majority of compressors used at the Dearborn plant were the cast iron Tecumseh.  By contrast the vast majority of service replacement compressors are of the aluminum York variety . The most logical explanation for a C8 marked York compressor ending up on a 1970 instead of a C9 or D0 compressor is that it was replaced with a service compressor.

[J_Speegle]

Something to keep in mind is the the vast majority of compressors used at the Dearborn plant were the cast iron Tecumseh.  By contrast the vast majority of service replacement compressors are of the aluminum York variety . The most logical explanation for a C8 marked York compressor ending up on a 1970 instead of a C9 or D0 compressor is that it was replaced with a service compressor.

My thoughts exactly but when looking at 70 Dearborn cars I found many more Yorks than the Tecumseh. Maybe something changed that year
Guess I could look at what the majority was (in my sampling) for 71 as a possible indicator

For others, overall it was easier to store the York style compressor since they didn't have the same rust issues since they would be sitting for years on the shelf and the  since they weighed so much less that made moving around, storing and shipping much easier

[hopey]

Engineering numbers(what I call them) that are found on the part are typically different then the part numbers that are used for inventory found in the MPC. The MPC will sometimes list the engineering number to identify the part also.In this case we are discussing what is typically found on the A/C compressor.

Yes Bob, but in this case I was explaining that not every PART number for items used to assemble the OPs 1970 Mustang would have a D0 prefix, but instead will be a smorgasbord of year code prefixed part numbers. Once that has been understood, then discussion can then move onto how the numbers stamped or cast into individual components relates to those part numbers.

If you read the OPs first post, he is asking why he has a C8 part installed on a December 1969 build date Mustang- he was expecting them all to be C9 or D0.

[Bob Gaines]

My thoughts exactly but when looking at 70 Dearborn cars I found many more Yorks than the Tecumseh. Maybe something changed that year
Guess I could look at what the majority was (in my sampling) for 71 as a possible indicator

For others, overall it was easier to store the York style compressor since they didn't have the same rust issues since they would be sitting for years on the shelf and the  since they weighed so much less that made moving around, storing and shipping much easier

My thoughts exactly why it seemed York style to be serviced with the most. But still a C8 marked compressor regardless is extra ordinary on a 70 Mustang from the factory and you know what they say about extra ordinary claims .