You might have a problem because brake fluid attacks paint really bad. Hope you have a good wax job.
To remove the brake fluid use WD-40 you need a oil to remove oil, brake fluid is a highly purified hydraulic oil really corrosive. Get it washed off with the WD-40 then use a good car wash soap to wash the truck. Be carefull and not to rub too hard on the area that the brake fluid was on. You may have to color sand or rubbing compount that area afterwards.