5er winterization question

[Howie]

I have a Cougar 303RLS purchased this year. I am getting ready to winterize and am wondering about using air or rv antifreeze. On my previous MH there was a valve just prior to the water pump that enabled me to suck antifreeze directly into the pump instead of from the water tank. This made it so simple to fill the system with antifreeze but current 5er does not have this option. In order to get to the water pump I will have to remove a couple of the under body wall panels to access the water pump I think (not sure of actual pump location). I have never used air to blow out lines but if I buy the air adapter to put on the water tank connection, how does the air push the water out on the line up to and after the water pump? If I put the air adapter on the city water connection I can see where it would blow out the water through to the facets when they are opened but that wouldn't account for the part of the line connected to the pump.

If I decide to access the water pump and put in a 2 way valve in front of it I could winterize with antifreeze but that would mean removing panels every year. Suggestions?