New Here and... First Question on 71 K20 Brakes

[A.Bursell]

Hello,

Been looking for the right truck for a long time, and I think I've finally found it. Will be picking it up at the end of the week. It's a 71 K20.

This is my first classic vehicle. I have owned many that were 10-15 years old at the time, but never anything as early as this. As such, I will be asking lots of questions. I've been lurking here and soaking up info, but only so much I can get without having my own to look at and ask questions about.

When I first drove the truck, I suspected it had a bad booster, as it really felt like manual brakes. Before I could make an offer, the owner had a mechanic look at it and scheduled a replacement of the booster. That is why I have to wait until the end of the week to pick it up. I also noticed some fluid around one of the rear wheels, not sure if from the rear axle or wheel cylinder. Couldn't tell.

One of the first things I would like to do on this truck is replace the brakes, so I feel good about driving it. How far should I go? I have no issue with replacing the master cylinder (if not done with the booster replacement). Should I? Should I also consider replacing the hard lines? Are they known to cause issues? I would also like to replace the rubber lines, as well as calipers, etc. just because of age. Am I ok buying these parts from RockAuto.com or should I source them elsewhere? I also plan to pick up the service manuals to help me along my journey.

Will I find any surprises with the brakes on this truck or is it pretty straightforward? Anything else I should inspect or consider replacing while things are apart?

Lots of questions I know! Thanks,

Adam