The ~0.25" I.D. Number 3 Water Bypass Hose is connected in parallel with the 1.5" radiator inlet hose and hardline. The #3 hose connects to the hardline that exits the cylinder head that also connects to the 1.5" inlet hose. Does the #3 hose purge the air that might be trapped in the hardline before the thermostat opens since the 1.5" hose takes a dip under the distributor before mating with the radiator? Once the thermostat opens there should be a high enough flow rate in the 1.5" line to move any trapped air into the radiators top tank. The 1.5" hose has 40 times the cross section of the 0.25" hose. What other function of the #3 hose might I be missing?
