i have a 1970 m35a2c and i have had problems with the brakes ever since i bought the truck. i dont know a whole lot about the truck let alone the brakes.
The manuals referenced above seem unbelievably cumbersome at first. Take the time. They seem cumbersome because they are quite comprehensive, and done at a step by step level. Once you become familiar they're still a bit cumbersome, but very, very informative and thorough.
does anyone know what the brake system is called.
They are power assisted hydraulic brakes. In today's world that is kind of "assumed" when you say "hydraulic brakes". It's a rather simple system once you have the overview. The power source for the assist throws a lot of people off. That's the first trick to working on these, don't make it more than it is.
If you're seeking advice from people you know, the closest thing to these brakes is the old Hydrovac units. Those used vacuum for the assist, this uses pressurized air. Very similar though. The hydraulic aspect is the same.
If you're seeking Google fodder, be very, very careful. Many different brake systems share common similar components, and the internet is full of more bad advice than good when it comes to hydraulic anything, and especially brakes.
and what a good resource is to troubleshoot them?
The TMs mentioned above are a huge resource for this and any other issues you may run into.
This site has tons of stuff as well if you use the search engine, duce brakes are a common discussion. You will have to weed through the posts that say "use the search", as it seems that there are as many of those as there are posts with good information, but it's well worth it.
You don't mention the specific issue you are having. These trucks aren't exactly new anymore, so really about anything "could" have failed, although some are more common than others. What's it doing that it shouldn't be?