Radiator Hoses
#1
Radiator Hoses
I have a 2014 ML350 Bluetec that had a leak at the upper radiator hose connection. I replaced both the upper and lower hoses with new OEM hoses from FCP, I did lightly wet the O-rings with new coolant, since the FSM has no specific procedure that I could find for anything special done to the O-rings. The new upper hose leaked in the same spot. I inspected the radiator for cracks and fitting roundness, nothing looked bad, but I replaced the radiator with a Mahle OE equivalent radiator also from FCP. I did learn while inspecting the radiator that it was a junkyard unit, newer (OEM sticker, and a Valeo date code of 5/19) but still being a unit from a yard I didn't feel too bad replacing it. But the new radiator and hose leak in the same spot when pressurized also, not nearly as bad as before. Is there a trick that I am missing? Is there an additive that I am supposed to be putting in the cooling system, like the old seal tabs on GM products? I am sure if grease the O-ring it would stop it, but that sounds like a band-aid at best. FCP is defecting the hose and sending me out a new one, but a bad new hose and all the leaks being in the same spot seem a little suspect.