Start the truck. Turn on the heater. Hold both hoses in your hands. The first one to feel warm is the inlet.
Heater coolant bypass pipe It would be the return hose for the heater.
one large hose from bottom of radiator to side of water pump. other large hose from thermostat housing to top of radiator. one heater hose from water pump to heater core, I think this one has a Y in it if there is a rear heater other heater hose from heater core to somewhere on top the engine. If there is a rear heater, its return hose goes to a fitting on the radiator.
Leaking head gasket ... return hose for the radiator ... heater hose, etc.
Slide out the radiator support remove fan and hoes. Separate by removing the old radiator support. Then replace it with new support, and return to brace and hoes connection. Pour coolant.
Your 1996 Chevrolet Corsica cooling system. Remove the water supply line and the water return line. Remove the heater core retaining bolts. Reverse the process to install the new heater core.
Lower radiator hoses in water cooled engines are return lines. The upper radiator hoses are feed lines of hot engine water to the radiator. The reason that lower hoses are cooler is that the radiator has allowed much of the water's heat to dissipate into the air. Thus, a lower radiator hose contains cooler water than other radiator and heater hose lines.
if a 4 cyc, it probably has a (silver) cap on the top of the engine where the return hose goes back to the radiator. thermostat is under the cap.
It shouldn't unless they are both drawing air from the same source.
First, make sure the engine thermostat is working. Do this by starting a cold engine and holding the top radiator hose. It should be cold, As the engine heats up, the thermostat will "open" and the hose will become hot, as the water is allowed to enter the radiator. Knowing you have hot engine water, find the fitting/hose at the rear of the engine, near the firewall. This is the hot water that waits to enter into your heater core, from the engine's manifold. Next to this hose that disappears into the firewall, will be a second hose that exits and runs back to the side tank on the top of the radiator. This is the return hose from the heater core. With the heat selector in "off", the return hose will be cool or cold. Selected to "Hot", the water will pass through the "now open" heater valve, through the core and back to the radiator. This makes that return hose warm/hot. Turning the selector back to cool will close the valve, and the return hose will cool. This is a non invasive method to check the valves ability to open & close IF the selector and it's control lines are working. The valve may not be receiving instructions from the selector. Another problem entirely.
To install the water return fitting above the ground pool, you have to switch off the source. After this you can then install the water.
Look in the yellow pages under "Transmission Parts". Go to them and buy the proper cooler. They will show you the proper way to install the cooler. Do NOT use an auto parts store. (The top line is from the trans. to the rad., the bottom line is the return. Fluid flows downward in the radiator.)
The top hose.