water issues

[thunderider]

my van was loosing water quik checked not going in the engine,then with the engine running found the leak,the pipe from the expancion tank to the water pump,at the water pump end,soo ill take the hose off and smear some good ol silicon on that end and slip the hose back on the water pump end,but what i notice while searching for leaks top rad hose is hot and the bottom hose is stone cold,could it be a faulty thermo?or air lock due to the leake