My coolant tank has two hoses going to fittings into the rear of the tank. It also has a large hose at the bottom that looks to go back to the radiator plus the normal overflow hose just below the pressuee cap. I understand the large hose at the bottom, but what is the purpose of the two hoses attached to the fittings at the rear of the tank?
JIm Shaw

The extra hoses are to provide coolant circulation in the engine when the thermostat is closed. This feature provides even temperature rise (no hot spots) as the engine heats up. In most engines these hoses also help to remove any air pockets from the engine when servicing the cooling system.

Gerald

They also may go to the high point of the coolent system to purge the air to the tank.