radiator hose hook up question

[Brently]

i have a radiator with the hole in it for the heater hose to hook up - it was plugged off when i bought the truck with the two heater hoses running to the intake and water pump - do i need to hook it up back to the radiator? if so where do i hook the other hose up? (intake or water pump?) the radiator hole was plugged with a wooden dowl and antifreeze runs out every time i run the truck - help! Brent

[JimKshortstep4x4]

As far as I can determine, it is pretty much an option. My radiator shop told me that it was fairly common for trucks to have the radiator with the heater return nipple in it when they had AC. It made for easier hose routing when the compressor was on that side of the engine.

I have tried to observe trucks to see how they were setup and have not seen a consistant practice. In the trucks without AC we
usually remove the nipple and solder a brass plate onto the radiator.

Jim

[400ex]

Yea. I agree with JimK. Radiators with the nipple were for trucks that had an AC. I recently replaced my old 4 core in my '71 (had the nipple for the AC) with a 4 core from a '72 that didn't have the nipple (O'reilly could not find one for a '71). Since I took the AC off, I just routed the hose from the radiator nipple to the water pump; no issues, end of story.

James

[Brently]

i have AC on the truck i am redoing - which hose goes into the radiator? and where does the other hose go to? water pump? or intake? is it worthy to run a hose in the radiator if i have AC or do i need to cap this hole off? help!! thanks, Brent

[400ex]

Well, if I remember correctly, on my truck the hose from the intake went to the top inlet pipe on the heater core and the bottom outlet pipe went to the nipple on the radiator.

Water flows from the pump through the heads up to the intake out the thermostat housing down the radiator and finally up the lower rad. hose to the pump again.

So water would flow out the intake hose into the top core pipe and then flow down to the bottom core pipe and into the radiator.

Someone correct me if I'm wrong....

James

[COBALT]

Without AC water comes out of the intake to the bottom of the heater core (5/8"), then through the core, and out the top where it runs to the input on the water pump (3/4"). From there water is run through the cooling jackets in the engine via the heads. If the heater is on then heat is dumped via the core into the cab so fluid is returned to the pump cooler than when it left the intake.

When the thermostat finally opens at the appropriate fluid temperature fluid is allowed up through the thermostat body up the top radiator hose where it flows down through the radiator, dumps out heat, and returns to the pump via the lower hose.