Brake chamber PM.

The last 30/30 can I bought was less then $40, if that’s the national debt to you replacing cans are probably the least of your worries.

 

Keep a halfback and diaphragm handy on the truck, if youre going to replace things preventatively, just do all the pancakes (diaphrams).

If the part you arent trusting is the mounting end, yes just replace all of em at one go.

 

Check out napa, grabbed me 2 30/30 when i needed a few tools for my car and saw em sitting there 2 months ago, cost was 50$ ea

 

I did all six on my truck this year. Also did s cams, bushings, slack adjusters, drums, shoes, bearings, hubs and caps. The whole deal. How do your s cams and bushings look? Might want to consider doing everything if you can swing the expense.

 

Not worry too much about steers, but would also change both hoses on each

 

No park brake diaphragm to leak

 

You can not replace the parking diaphragm. That's the one that usually causes the trouble. Or a broken parking spring.
From my experience, you are quite right. If one goes, the others are not too far.
Getting stranded at the side of the road due to too much air loss and the other chambers apply the brakes can get costly.
I did the rears all at once at some point. A few years later, they all failed again within a year.
I do carry the rear part, a clamp and a diaphragm with me. Just in case.