roaring engine when starting , squeeking brakes in the rain on 2001 Toyota Tundra

when starting the truck the engine roars for a minute or two and then settles down, is this a tranmission issue? When it rains the breaks squeek like metal on metal and I have to pump them to get the brakes to stop squeeking . What could be the problem?

Asked by for the 2001 Toyota Tundra
Roaring sound when the engine first starts may be normal it may be the viscous coupling cooling fan hub. The brake noise to may be normal if inferior brake pads are used but safer to get both items checked as this is just a guess as I cannot hear the noise first hand.