the upper hose going to the firewall connects to a plastic gate valve with a wire cable controled by the temp slider lever on the dash.It’s starting a slow leak and I don’t need a heater so I want to cap it off. Should I cap the other end of this hose at the water distributor(for lack of the name) ? Also I have often wondered if there is a chemical which could be rubbed on the male metal stubs? to prevent rust BUT not be slippery for the radiator hose to clamp on. Maybe a rust coverter primer. Both my toyotas are 20 yrs old…thanks, Mike
I don’t really like the idea of capping off the heater core but here’s how to do it. Just loop a piece of hose and clamp it to the heater core inlet and outlet. The remaining hoses from the engine need to be connected together with a plastic or metal coupler so that coolant can flow properly. You can pick up a straight coupler at most auto parts stores. The best course of action though is to repair the leak and leave the heater core operating as it should.