if it pulls to the left when you brake then look to the right front caliper not doing its job ,(when it pulls its because only 1 side works and that wheel does all the work so it turns in to it )
bleeding it might fix it for now but it is better to take the pads out and work the pistons in and out a few times to clean the pistons + you can see if it the pistons are all cruddy and need new ones
to get the pads out use a hammer and punch to drift the 2 holding pins from the top of the caliper then use a big flat blade screwdriver to push the pads back into the caliper and lift the pads out ,take care not to damage the friction lining when you push them back