1942 hose arrangements

[gary griffin]

   I have seen various hose arrangements in 40's Cadillacs.   1942 was the first year with the Deluxe heating system and also the thermostat instead of the shuttered radiator. (In Germany I owned a 1950 Mercedes 220 sedan with shuttered radiator but as I recall it was manually controlled by a lever under the dashboard). 
   It appears to me that there is a bypass hose that allows some water to circumvent the radiator? If this is so how does it interface with the heating system return hoses?
   I have seen small angle valves on the return to the water pump. Were these original and if so is there a correct diagram for the small hoses and valve. It would seem that if there was a valve on the return there would be one on the supply? Being in the hydroponic heating business we always installed isolation valves. If I were not going for authenticity I would have valves to shut off flow if something is leaking such as hoses or heater.

[Bill Ingler #7799]

Gary:  When Cadillac did away with the shutters and starting in 42, the thermostat was relocated behind the top of the radiator in the fitting that accepted the water from the left and right head. Until the water in the engine was at the correct temp, the thermostat stayed closed. To keep circulating water in the engine with the thermostat closed, the outlet for the radiator hose from the left cylinder head has a 5/16 hose nipple for 5/16 by-pass hose as shown by the arrow in picture 1. That hose went across the front of the engine into the 5/16 nipple on the top of the water pump shown in picture 2.

I know of no other shut off valve location, for the water for the under seat heaters, than the valve in the line for return water from the heaters that goes into the water pump as shown in picture 3. I have seen 2 ways of installing that shut off valve. With an extension or the shut off screwed directly into the water pump. I elected to use the pipe extension as it makes the hose run too close to the exhaust pipe without the extension. Bill