Heater Hose with "T"

I have seen a number of builds with a "T" installed in the heater hose between the heater hose leaving the motor and the hose attaching to the heater control valve. Can anyone clarify what that "T" is for?

Ken Roberts

It goes up to the bottom of the coolant expansion tank . That's how the C6 Corvette routes it.

The Tee is installed in the 3/4" line though. That is the coolant returning from the heater core.

The 5/8" line is the coolant leaving the engine and going to the heater core.

Se my post here for a good source of "T"s and hose size adapters.

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