I'm replacing the front passenger side caliper. When I removed the old caliper, I let the brake line hang and allowed the brake fluid to drip out. It's been a week since and the MC reservior is empty now.

 

I was planning on bleeding the brakes once everything was back together, but I've seen some talk on the forum about bleeding the MC as well. Is this something you only do when you suspect an MC related problem? or should I plan on doing this before bleeding the brakes?

you may need to if you cannot bleed all the air out at the wheels. try gravity bleeding first(add fluid to the MC and let it flow out the bleeder) if that does not do it go to vac. or pump methods. I would save bleeding the MC for last if necessary. it can be messy if you dont have the little adaptors that thread into the ports.