I am no expert, novice beginner at best. But I just finished tearing down my Series 1 Variable Speed head completely and rebuilding it. My brake shoes were in decent shape, so I didn't replace them. But the springs between them needed replacing.
To replace the shoes, I would have to do quite a bit of disassembly. The motor has to come off first and foremost. Then the upper belt housing. Once that's off, the top variable speed pulley needs to come off. Then the middle belt housing base has to come off with the splined shaft and bottom pulley. I can turn that over and there are a couple screws that hold the belt housing base to the brake bearing cap. Once those screws are out, I should be able to tap out the spindle pulley hub and get to the brake shoes.
There might be a much easier way that requires less disassembly, but I don't know what that could be.
If it were me, I would check the top bearing and the bearings on the sliding housing and brake bearing cap. They're cheap and easy to replace. I'd probably replace both belts, too. On mine, the brake bearing cap had small cracks though the threaded holes where it mounts to the middle belt housing base, so I had to replace it.
And if you've gone that far, might be worth replacing the grease around the bull gear. You've almost disassembled the whole thing anyway.
You can check out H&W Machine Repair and Rebuilding's YouTube channel for a bunch of videos on the Bridgeport.
I also made a series of videos on what I did to mine:
https://www.youtube.com/playlist?list=PLW5c7JLIWe3-1NjgH_X4M3-fWSfdIaHnO
Disclaimer: My videos are "How I did it and what happened" and not intended to be a "How to do it" series. I'd point you to H&W for that. Follow my examples at your own risk and peril.
