Rattle, Yes heater flows all the time. Doesn't work worth a snot when cold, but great when it's warm!
I have one in my 54 like that. There is a valve to go into water pump from Chevs of the 40s like someone said. I just got new catalog. I'm wondering if it is problem holding back the flow for pump or if water goes bad in lines to heater and it's core from not moving or what? Seems like any rust would settle out and clog the heater there later. Between the heater and the exhaust heat, engine heat coming up thru a bare floor it works too good in summer! :rolleyes: I'm glad I got mine, mostly for defrost, which only works half-*ss too. Heat in these old rigs is marginal at best. What were they thinking??
