Can anyone tell me what is the water flow direction, through a heater core, on a '95 S-10? The inboard (top) hose goes to the water pump and the outboard (btm) hose goes to the front part of the intake. I'm not sure if the water pushes or pulls water through the heater core. Thank, Rich

 

The short answer is "it does not matter" since this is a sealed "closed loop system", a restriction at any point will slow or stop flow and reduce or kill the heating system.

The longer answer is that the water pump on a Chevy has one inlet (lower radiator hose) and several outputs (casting to block - and heater hose). So, the water flows from the pump thru the host to the heater core then returns, either to the intake or the the radiator passenger side (depending on model).

 

Thanks. From what you mentioned, closed loop system and several outputs, makes me think the supply (or pressure side) would be the heater hose coming off the top of the water pump. Thanks again.