Posted by john k. seidts on July 23, 1999 at 21:47:09:
In Reply to: WC Radiator posted by Jim C. on July 22, 1999 at 18:25:14:
I am not familiar with the 1/2 ton engines, but the water distribution tube fits from the front to the rear of the block behind the water pump. This tube directs the coolant onto the area immediately beneath the valve seats, to keep them cool. This tube is made of copper, and if coolant pH is not watched, the copper gets nasty. We had an M37 with a blockage in this tube, and it at one point exhibited the symptoms of heating, right before one of the valve seats came loose and went into the cylinder. Might be worth a water pump gasket to check it out.