Hello to all.
I still am not sure of the true function of the "surge/cooling" box which is mounted above the engine.
that surge box that you refer to is most likely an engine cooler. when pumping there isnt enough cooling taking place with just the fan. there should be two lines, one coming from the pump to the box and one from the box back to the pump. the box is a liquid to liquid heat exchanger. inside the box may be some type of coil to keep the pumped water from actually coming in contact with the trucks cooling system. if you trace them out youll see where they connect to the pump. there may be a valve to isolate the pumped water from the box. over the years due to corrosion the coil indie the box leaks and then you can loose all the water from the trucks cooling system. pic #32 shows how its connected to the radiator and the pet cock closed on top thus isolating the fire pump water. in pic #33 follow the red hose thats coming out of the box and trace it. in pic #35 it looks like the fuel line to the fuel pump is missing. #36 looks like the radiator is leaking or from years of splashing fire water in the front of the truck and the rust formation is from that. the reference pic and pic #1 looks like the pump pressure governor. in pic #3 the the little gear is driven by pump pressure and regulates the butterfly below the carb thus regulating discharge pressure from the pump. in pic #8 what do the gages read, pressure or vacuum and is that a temp gage on the fire wall? pic#23 looks like its a 500 gpm pump. there should be a tag somewhere up front on the pump itself saying what its rated for. pic# 26 looks like one line goes to the red box and the other line may be for the pump governor control. the engine should be a 302. hope this helps
