Looking for info from other action line owners. My GMC C25 has a straight 6 250 engine. In addition to the normal upper and lower radiator hoses it has a smaller hose coming out of the bottom right of the motor and spliced into an additional hose below the thermostat. I've searched for hours and I can't find diagrams or references to what this is. Its like it doesn't exist. Does anyone know what this is and how it's supposed to be setup?

The way it was plumbed when I got the truck is the weird splice was connected to the right side, of the iron lower thermostat housing, below the thermostat. The smaller T splice ran to the back right of the engine and the other side was blocked off with a lugnut. The heater core hoses are on the left side of the thermostat housing where they normally are, temporarily looped off while the heater core was worked on.

 

Could this truck have had an external radiator?

 

I'm not sure Kevin. I've never seen an extended radiator and overall this truck seems to be very base model as it doesn't have ac or power steering.

 

Could it have been part of a coolent warmer system? Truck live in a cold climate?