Drum Brakes

I am about to go through the process of redoing my drum brakes. I was wondering if I should replace the master cylinder before or after I go through the wheels or if it matters when I replace the master cylinder? Also, can I bleed the master cylinder while it's on the truck or does it have to be bench bled? Do I bleed the wheel cylinders after I replace each individual one or can I do the bleeding after all the wheel cylinders are installed?

It would help if there was a little more info about your truck (what year, model, etc) Do the brakes work at all? Has it been sitting forever?

In general my advice is this.

Whatever you do, do not damage your drums. Some models/years are no longer available.

Since you are talking about master cylinder and wheel cylinders together I am assuming you will be performing a total rebuild. So, my advice...
New wheel cylinders, new master cylinder, new rubber hoses.

To bleed the lines, you always start the farthest away (passenger rear).

Open the bleeder valve, put fluid in the master cylinder and pump the brake pedal (very slowly) It is best to put a hose over the bleeder valve and let the fluid go into a clear bottle (water bottle) so you can see what is going on and this helps keep things tidy.
check the fluid level often, keep adding fluid, do not let this run dry as it will introduce air bubbles and complicate things.
Do this until clear fluid comes out of the passenger rear cylinder. Close the bleeder valve and move to the next wheel.
Repeat this process for the other 3 wheel cylinders. Keep in mind you probably will not get a 'stiff' brake pedal until you are at the last wheel cylinder (drivers front)

Once you get the hydraulic part of the brakes working, I would go back to each wheel and adjust the shoes.

This takes some time but if you are patient you will be rewarded with a refurbished brake system that will work for years to come.

Kerry

^^^^ and yes, you have to bench bleed master

It really helps to have a partner to help with the bleeding part of the job! That is unless you have an actual power bleeder.