The Stovebolt Site Forums The Shop Area Engine Shop 1959 Apache cooling system / deluxe heater inlet

I'm trouble shooting why my cab heater is not putting out heat. I took the heater inlet hose off the heater as shown in the photo (the hose resting on the battery). I expected to see water pumping out of this hose while the engine is running since the hose is connected just below the thermostatic housing. No water is pumping out on a cold engine. I did not wait for the thermostat to open.

Photo
https://swenracer.smugmug.com/Trucks/59-Apache/i-mBk88Jz/A

I have all new parts in the cooling system (radiator, thermostat, heater core).

Does anyone know if the heater inlet hose should always have flow from the engine or does this only work when the thermostat is open?

Even with the thermostat open and the heater hose hooked up, I don't get any cab heat.

Thanks in advance for any ideas to help figure this out.

maybe the flow TO the heater comes from the water pump, the hose to the thermostat housing would be the return .... have you tried it with the other hose off?

no heat could also be a plugged heater core or defective heat control [ranco] ... is this a recirc heater or deluxe?

Bill

Thanks for the feedback Bill. I do have the deluxe heater with thermostatic control.

I did pull off the other hose and still had no flow with the hose raised above the radiator (engine running). Both hoses flow water if lowered below the top of the radiator.

My assumption on water flow to the heater is, the water pump pulls water from the lower radiator hose would also have to pull water (return) for the heater. Maybe this is not correct?

Scott.

Scott, you are correct. The heater feed hose is the one attached to the thermostat housing and coolant should flow whether or not the engine is hot or cold...or if the thermostat is open or closed.

The heater return line connects to the water pump.

It sounds like you might have some corrosion blocking the feed line fitting that screws into the thermostat housing.

Good luck,

Matt

Turns out that I had blockage in my heater core. Once I flushed the core out I started to get heat in the cab. I also found that I needed to re-adjust the heater valve cable to make sure the valve opens all the way. I removed the little spring that comes with the heater valve. This spring actually worked against me in allowing the valve to open all the way.

I also observed that there is very little warm/hot water circulation in the heater core when the valve is open and the truck is only idling. The real heating comes when the RPM's of the truck are higher than idle.

I've posted a video of the heater core water flow for others to see.

https://swenracer.smugmug.com/Trucks/59-Apache/i-x9nTMRn/A

Scott.