Degas tank hose connections

[Doad]

Chevy 2005 Equinox,dealing with coolant loss issues as discussed in the "Cooling System Fluids" page. Figure this is a mechanical topic....The degas tank. Everyone has a different view on how EXACTLY this operates, so I'm a bit confused.

On a Chevy Equinox degas tank there is a bottom hose which looks like it goes to the heater core (?). Then there is a smaller diameter hose at the top of the tank that gets warm pretty fast. What does this hose do and what in the flow of the coolant in respect to these hoses, heater core, engine and rad ? And I assume the degas tank also acts as an expansion tank as the coolant level seems to rise when hot......

Thanks

 

[eljefino]

I assume the top hose goes around to the top of the engine somewhere. This may, at times, hold pressurized "gas" as in bubbles working their way out of the engine.

The bottom hose typically tees into the heater core/ bypass lines, 5/8-3/4 inches in diameter. If the system coolant is low the water pump effectively sucks on this line and drains the tank.

I had a saturn s-series that was stubborn to burp air. My answer was to detach the degas hose and start it up. Eventually, a burp of coolant shot through, and all was well. But normally the gas should find its way to the surge tank and once the 18 psi of the cap is reached it'll find its way out.