Packard Forum Index » Post-War (1946-54)

Back when I was considering my car for purchase, the owner explained that he had replaced the heater core but that something was still leaking. He gave me the original core that he had taken out but I'm quite sure that the coolant leak was originating from the seal in the thermal valve and not the core itself. The leak probably explains why the passenger side floor pan had rusted through and been patched with fiberglass but since the heater is currently bypassed, I need to reconnect the hoses to the heater so I can confirm the source of the leak. I performed a search on the subject but couldn't find a schematic showing how the hoses are routed between the cylinder head and heater box and the water pump and heater box. I checked the manual under the "Accessories" heading and it explains how to install the heater but does not go into any details concerning hooking the hoses up. It just says "remove the plugs from the cylinder head and water pump and connect the hoses".

I don't recall a diagram for 51-4 but here is one for 50 and 55. Basically the same flow except for the V8 feed being different coming off rear of engine instead of top. The valve needs to have the input from the head on the curved pipe and output to the core on the straight length. It looks like they choose the bottom connection to the core as the feed side although I doubt that part really matters.

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That's the diagram I was hoping for Howard. Thanks for posting it and for clarifying the procedure since the hoses could easily be connected up wrong.

Howard:
I own a 48 and 49; and sold a 49 and 50 last year. All 4 of these cars did NOT have the heater hose connected the way your diagram shows. The cylinder head hose went to the Top heater input and not bottom.

Also, 2 of these cars were a restoration by Custom Auto in Santa Ana, and Cal knows what he's doing.

So I'm confused about what's going on with the hose routing.

Orv

Not sure what to say on the work by Custom Auto.

As far as in and out of the heater core, I don't think it really matters although if the angles shown in the drawing for the metal core tubes are correct, it seems like that would be a smoother and maybe shorter route with no 180 degree or sharp bends.

The important part is the pressure or flow direction thru the valve. The yellow illustration detailing the 22-23 series is from 1950 Service Counselor Vol24 #2. It shows what Packard says is the proper hose and flow routing to avoid intermittent complaints of heater valve flutter noise. Article with the illustration explains why they want it done the way drawn.

Nothing definitive to be learned by looking at existing cars, restored or otherwise, as they all have so much prior history of maintenance and repair. And I agree HH56 that I doubt it has much effect on the performance of the heater itself. But if you look at other source documents, all 48 thru 56 are essentially the same, the water feeds from the point of the hottest water, the cylinder head, to the valve and then to the bottom of the heater core, and then the cooler water returning from the top of the core to the water pump or water pump manifold (V8).

Perhaps this will help.

Top outlet of heater core along inner fender behind fan to water pump.

Outlet from top of head to bottom inlet on heater core. Sorry I don't have a better view available right now. I can either go over and photograph right side or this may be enough for you.

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