Recently, i've picked up a Lews Magnesium Pro reel and haven't used it much since it's been winter. After fishing with it for two hours, it stated making squeaking noises and overall not seeming very smooth and being kind of difficult. I'm not very familiar with the external braking system so i'm unsure if that could be a problem. i was casting a 3/8 oz Swim Jig with a small trailer and not experiencing any backlash and casting an average distance. I'm not running heavy line either, just 12 lb. mono. can anyone help me out?

When do you notice the squeak, on a cast or during the retrieve?

Could be the brake tabs rubbing the brake drum. I had this noise on my BB1 Pro with similar brake system as your reel. I oiled the drum lightly but noise still there but you can try it see if it helps. I did notice the NEW BB1 Pro has QUIET CAST feature so this tells me it was a common problem. Add a drop of oil to the spool bearing as well. or take them out clean real well then oil.

See video 

 

 I always had this problem with Lew's ACB reels. Like the video says, just put oil on the race and it's ok.