my truck pulls to the left when braking, any ideas on how to fix it

 

You might want to take a look at the brake pads and rotors. If either of them are worn down too much on one side then it will pull to the other side, or if the rotor is warped. Another idea for you to look into would be to check out the caliper on the driver side because if it is sticking (caliper pins) then it will give you that problem too.