Early version RC-15 Radiator Cap

[David L.]

I bought this RC-15 radiator cap today at a swap meet in Amherst, NH. I cleaned it with my wire wheel and a Brillo pad. It does not have the encircled AC. Does anyone know when the encircled AC was added?

According to my research the RC-15 cap first appears in my 1964 Chevrolet Parts Catalog (Oct. 1963) for use on 1964-1964 Chevrolet Passenger cars w/ AC, GM # 861050, in Gr. 1.203.

Chev. & GM Parts History:
861050 to 3886273 in Jan. 1966 to 6410456 in Mar. 1973 and back to 861050 in July 1973.

The 1966 Corvette AIM lists GM # 3887586 and # 861042 (opt.) as the radiator cap w/L72 engine.

Dave

[Joe L.]

Re: Early version RC-15 Radiator Cap

I bought this RC-15 radiator cap today at a swap meet in Amherst, NH. I cleaned it with my wire wheel and a Brillo pad. It does not have the encircled AC. Does anyone know when the encircled AC was added?

According to my research the RC-15 cap first appears in my 1964 Chevrolet Parts Catalog (Oct. 1963) for use on 1964-1964 Chevrolet Passenger cars w/ AC, GM # 861050, in Gr. 1.203.

Chev. & GM Parts History:
861050 to 3886273 in Jan. 1966 to 6410456 in Mar. 1973 and back to 861050 in July 1973.

The 1966 Corvette AIM lists GM # 3887586 and # 861042 (opt.) as the radiator cap w/L72 engine.

Dave

Dave-----

I don't know the history of the changes for the embossments on the cap. However, I believe 861050 is an old AC Division part number. 3886273 is a Chevrolet part number (probably for the 861050 cap). 6410456 is a newer AC part number (but still old considering it's probably at least 50 years old now). Why they went back to 861050 I have no idea but I have seen this sort of thing happen before, particularly with AC Division parts. I doubt that any of the part number changes was related to slight differences in the embossment of the cap (e.g. the encirclement of the "AC").

[David L.]

Re: Early version RC-15 Radiator Cap

Joe,

861050 may have original been the AC part number but it is also a Chevrolet part number as it it appears in my 1964 (Oct. 1963) Parts Catalog as well as Chevrolet parts catalogs issued after July 1973.

I guess my question should have been as follows:

Were the 1966 Corvettes w/427 engines issued the RC-15 radiator cap as shown in my photo or was this cap issued on 1963-1964 Chevrolet Passenger cars w/AC?

Dave

[Joe L.]

Re: Early version RC-15 Radiator Cap

Joe,

861050 may have original been the AC part number but it is also a Chevrolet part number as it it appears in my 1964 (Oct. 1963) Parts Catalog as well as Chevrolet parts catalogs issued after July 1973.

I guess my question should have been as follows:

Were the 1966 Corvettes w/427 engines issued the RC-15 radiator cap as shown in my photo or was this cap issued on 1963-1964 Chevrolet Passenger cars w/AC?

Dave

Dave------

861050 does appear in Chevrolet P&A catalogs as well as Chevrolet price schedules. However, it's still an AC part number. It's simply that it's an AC part number used on Chevrolets, so that's why it's in the Chevrolet parts references. You would likely also find it in the parts catalogs of other GM car and truck lines on which it was used.

I do not know if the cap of the exact configuration and embossments as the one you picture was used on 1966 Corvette with 427. The RC-15, of course was used and was used on many other GM applications of the period with 15 lb systems, copper/brass radiator, and no original coolant recovery tank.