Heater delete

[Kasper Cummins]

I'm pulled the heater out but I'm not sure if I should plug the coolant ports or keep a loop? Main just worried about pushing the freeze plugs out.

[monoblock]

A loop is usually better because it preserves the designed circulation system.
Some vehicles (ours?)are designed to continuously circulate through the heater core as part of the cylinder head cooling circuit.Your heater control may only operate air-flow flaps,not coolant valves.If you plug the old heater supply/return nipples you block circulation around the cylinder head.
Hopefully someone can confirm if ours have this design or not.

[BobS]

A loop is usually better because it preserves the designed circulation system.
Some vehicles (ours?)are designed to continuously circulate through the heater core as part of the cylinder head cooling circuit.Your heater control may only operate air-flow flaps,not coolant valves.If you plug the old heater supply/return nipples you block circulation around the cylinder head.
Hopefully someone can confirm if ours have this design or not.

If you go out and pop your hood up you will see a vacuum operated shut off valve located near the firewall that controls the coolant flow through the heater core. If the valve is open then the air going through the heater/AC passage gets heated. I believe this only happens when the heater control is set to the defrost position.

The industrial Cummins engines have threaded plugs where the heater hose nipples are attached. This would be on applications such as drainage pumps and wood chippers. This info is from my past encounters with 4B & 6B industrial engines.

[monoblock]

Great help,good to know,Thanks