showcrop
Well-known Member
I drive a Mack dump truck now and then. Today I hauled one load with a 2013 Granite then worked on it the rest of the day. The problem was a 3/8 rubber hose from the water pump to the expansion tank. It is held in place at both ends by a push on plastic fitting that seals by an O-ring. The expansion tank had just been replaced, and suddenly coolant was pushing out a big stream past the O-ring. Long story short, The rubber gets stiff, and puts a little side pressure on the fitting and breaks the seal. When I went to get a new hose, it had been superseded by a silicone hose, which of course will stay flexible. At NAPA they said that these plastic fittings are common on a lot of vehicles now. I am suggesting that you check your cooling systems on all vehicles for these plastic fittings and if the hose is rubber replace it with silicone ASAP.
