I think this would be the best place to ask this question. So I am wanting to do a 12v cummins swap into a 52 chevy 1 ton for a 5th wheel pulling truck. I want air brakes because I think they are cool and have never used them before but heard they are great for loads, and this truck will be pulling trailers with loads. I looked and can find medium duty semi axles with air brakes on them so thats not the issue, the issue is that I cannot find out what air pump i need, for enough cfm to keep the tanks full and not run out. I know the 12v does have a mechanical air pump that was on it for small rigs but they are expensive and it seems like i have to put it in place of the vacuum pump, which i wont need anyways, but it takes some fab work and im new to fab work. i was hoping i could find a belt driven or electric air pump that would either mount on the front of the engine for belt or under frame for electric. what might work best, and you guys can tell me yeah or nah, is if i put a belt driven air pump on a steel plate and bolt a small electric motor to it so the engine is not driving the pump and then the govenor turns the lectric motor on and off as required. could that work? i could put that on the back of the flat bed. please help me out here and thnx if you do!

 

Don't forget the windsheild wipers on a 52 are vacuum operated, so if you get rid of the vacuum pump, you will have to retrofit the wipers. (Pretty easy to get)

 

I suggest you find a mid/late 90's Freightliner FL70 or Ford F600/700 to study. Many are 6BT airbrake trucks.

Then decide if you're ready to do a body swap, or simply swap good 1ton/1.5ton axle(s) into your classic truck. Add an exhaust brake for good measure.

And before you begin, figure out what your GVWR and licensing obligations are. No sense in building a truck that requires a CDL, and can't be road legal because its curb weight is heavier than its GVWR.