30/30 Brake chamber

The port toward the rod supplies air to release the brake, rear is to apply brakes. I'm not sure what your application is but I don't believe this is going to do what you want. You need a regular pancake style like on a steering axle.

 

I think you got that backwards. the front port(the one closest to the push rod applies brakes. the rear port releases the park brake. but yeah not sure how that will work in your application unless you cage the park side

 

I've never seen one either but, it's not a high pressure type connection.

 

Your right @lester , posting past my bedtime is bad.

 

I see no drain holes. I would say the tube is to keep pressure equal or vent?

 

Used to expel air from the back of the diaphragm. Kind of bounces it back and forth. If you look there are no other vent holes. Great for mud runners, liquid nitrogen sprayers and such. Keeps all that junk out of the chambers.
Sounds like he could use just a basic single service chamber but I am sure he has something worked out by now.

 

Some older ag trailers and especially lowboy and tank trailers only used service chambers. The park brake was applied by air when the gladhand is disconnected. If the air bleeds off your park is gone. It was common to hook up the gladhand before connecting to charge the trailer before backing under.

In order to install spring brakes you would have to replumb and different brake valves.