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Fred T · 12-14-2005, 10:49 AM

If you're concerned about water flow, don't be. The AC equipped trucks have a vacuum operated valve that shuts off the water flow to the heater.

In high school my buddies told me you needed the heater hose connected for flow so as not to overheat the head. I have since learned that on older chevies with the 261 that the hose is needed, they tend to have steam develop in the head. For the other engines, no.

12-14-2005, 10:49 AM	#11
Fred T Cantankerous Geezer Join Date: Aug 2002 Location: Bel Aire, KS Posts: 6,264	Re: Heater core basic question If you're concerned about water flow, don't be. The AC equipped trucks have a vacuum operated valve that shuts off the water flow to the heater. In high school my buddies told me you needed the heater hose connected for flow so as not to overheat the head. I have since learned that on older chevies with the 261 that the hose is needed, they tend to have steam develop in the head. For the other engines, no. __________________ Fred There is no such thing as too much cam...just not enough engine.