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

So from the water pump the hose goes to the fire wall inner tap
Then out the outer tap to the lower tap on the core then out the upper tap to the head ? Does that sound right ?
I have a always on problem and want to make sure the heaters plumbed right

It is really not that critical function wise as everything is in series. The hot water outlet is the fitting on the head and for best control would go to the valve first and then the heater(s) in series with return to the water pump. One thing mentioned in a service article on the 48-50 valve is to have the hose from head go to the small curved tube on the valve and the straight tube on valve to heater core. That prevents an intermittent clicking noise as the flow is not trying to force the valve open. No mention of that in later install instructions but since that portion of the valves are virtually identical it probably is still a valid suggestion.

Since Packard did not see fit to publish plumbing info in the 51-4 manual here is the layout from a 55-6 manual. You can duplicate the routing and substitute the hot water outlet fitting on top of the 52 head in place of the V8 fitting which was next to firewall on the end of head. The return hose clamp is on the 52 fender instead of the engine but otherwise the hose routes are virtually identical. If you don't have the underseat unit then ignore those 2 hoses and use the top heater fitting to return to water pump.

Attach file:

---

  (65.92 KB)

Man I really had this MESSED Up! I thought the hot water " out" was the tap on the water pump but looking at it I guess I had it backwards
I ve "y"'d the hose to feed a parrelel loop to heat the dual intake manifold I installed
So how I have it now ,understanding from what you said the top of the head is the "out",
It y's and goes through the manifold with one part and the other is going into the top tap of the heater core going in
The side lower tap takes the hose to the outer tap on the firewall this is the part where I can't tell which part of the switch it's going to buts it's the fender or outer side one
Then the inner tap on the firewall is the out from the switch and rejoins the manifold loop to go to the top of the water pump and then to the bottom of the radiator which I guess is the I. For the radiator
The heater core in your pic looks like it had 3 taps !
The valve which would have the curved elbow you mentioned is in a box of some sort where I can see which is which attached to the passenger side of the fire wall

As mentioned, function wise it doesn't make much difference as far as the heater. Whether it will to your manifold I can't say. The hottest water is coming off the head and is pushed out that center opening because the pump is pushing water returned from the radiator into the front of block. The heater port opening on the pump is actually in the return from radiator hose side. Whether the degrees of difference in temps is going to make that much difference in a moderate climate is a question. If the car was in the Arctic circle then it might.

I agree the illustration is not the best but better than nothing. The valve is in the same location on your car as the 55-6 and is almost the same valve. Believe the sensing element and works portion on the inside of car may be a bit different to better catch the flow of hot air from the different plenum layouts but the valve portion is the same.

The water flow on that V8 illustration is out the end of head, under heater core to valve, out valve up to bottom tube of front heater, out top tube to underseat heater and out underseat core to the water pump return. All components just have the two ports -- in and out.

Attach file:

---

  (57.85 KB)

In terms of basic function it really doesn't matter which hose you select as the inlet to the heater core and which the outlet - the coolant flow in the engine determines which way the water will flow and the heater core will get just as hot in either direction. The only difference is whether your heater control valve (Ranco or otherwise) will be regulating the flow going to or coming from the core but the function still remains. That said, why not hook it up correctly.

Ok I think I have enough from the pic and everyone's comments to route it right now THANKS !,
,I'll get a bunch of heater hose and have a plumbing party ! I may put a shut off valve on the heaters inlet if I can as I live in million degree Houston

When I was looking for that switch under the dash I found the heater duct that runs to the center of the passenger side of the firewall ( defroster?)was old and decaying so I'll try to replace this while I'm fooling around under there
What about this mysterious switch tho ,time for it to come out for inspection ?

What does the mysterious switch look like and where is it located?

The tube under dash is for the defroster. Inside that square black box is a flapper valve operated by the heater/defrost portion of the right lever. It directs air to the cardboard plenum running across the firewall or to the tube or both.

The thermostatic valve should cut off the flow of hot water but it is possible it started leaking and has been disconnected or is not working or cable is misadjusted. You could either repair that or get one of the cable operated on/off valves for the hose and have the temperature valve cable portion of the left lever work that valve instead of the stock valve. Have to make sure you get the correct type orientation on the valve so it works with the cable setup and the on and off will match the control labeling.

The flapper valve in the vent tube under the heater box operated by the right lever air cable should cut the airflow off to the heater so no hot air comes thru. The rubber on those flappers is old and frequently breaks off so it could be leaking air or cable could be misadjusted. In Feb 51 Service Counselor 25 #2 is the procedure to adjust the cables on those dual function levers.

Thank you!,,