When you change the brake master cylinder, make sure you have plenty of tools, a concrete pad to be working on, and a plan. Did I mention tools? You will find the manufacturer installed the MC first than built the rest of the truck around it. The best way of getting to the top, outside bolt is to have a 9/16 deep well socket, a six inch extension, a universal joint extension, a second six inch extension, and a ratchet to thread through the frame hole where the back of the MC is connected to the line going to the air pack. That, and taking the rubber boot off the front of the MC while removing/installing it and it's "easy". And check your wheel cylinders to see if they have a cup inside the rubber boots, or just the spring. DO NOT discard those cups if you have them. Learn to search the threads here by finding what others have said on their behalf.
