Originally Posted by signalderivation
If you don't have a diesel coolant heater you won't lose anything by removing the pump. The engine will pump hot water to the front through 1"-1 1/2" hose without a problem.
If you do have a coolant heater you'll lose the ability to run it for any practical benefit without the engine running.
With a rear engine, keeping the coolant pump even if you remove all the heaters except the front one, will help defrost the windshield more quickly.