Hate to let some of you know you are wrong. But here goes ..I have a 1958 cameo with dealer installed Chevrolet Cool pac a/c. It was a first put on Chevy trucks in 58 though 59. In 1960 the black Under Dan unit was redesigned to a white plastic case under dash model also called coolpac. Made by Chevrolet it had the same compressor as the Cadillac along with a valve that bled high pressure side to low side to regulate temp. I have the reprint service manual for mine. Thing is besides mine in 16 yrs in the hobby and on Internet I've only seen one other 58 with it. I bought a recently available rebuild kit for the above mention high press bleed off valve from Curtis at classic auto air company in Fl He has been working on vintage caddy a/c restoration for 40 yrs and had only seen or heard about a handful of the 58-59 apaches with a " Chevrolet Cool Pac". After flushing and new oil and coolant upgrade. Mine works now after waiting for a chemist to come up with a product autible for the valve rebuild diaphragm for 10 yrs. I haven't mastered the photo add on this site and am usually on my iPad. My truck was built in California and was a heater delete truck as the under dash unit prohibited the use of standard heater. However I've modified bothe to allow the heater to fit I'm sure not May were sold as they were trucks after all and a/c had as mentioned above were only for luxury cars to that point. Agin 1858 first yr offered for Chevy trucks. Not sure about Gmc. The coolpac logo has cool pack by Chevrolet and bow tie embossed on in cab unit If anyone who wants picture of unit and under hood and service manual (1958 ) IM me a email or I can send by text. I'll try to upload here as well if I get on a PC. Classic auto air 81 251-2356
Last edited by txpete; 03/28/2018 1:18 AM. Reason: Spell correction
