Backflushing

[ardnum]

I wanted to back flush the coolant in a 1998 Mazda 626 automatic (6 cyl).

I purchased a Prestone back flush kit. The instructions say to connect the "T" to the hose that goes to the top of the engine and not to the hose that goes to the water pump.

I located two hoses coming from the firewall and they both seem to be going to the top of the engine. How do I identify which hose goes to the water pump and which does not?