Overpriced given the cost of the components in this filter set. Brass ball valves started leaking in less than 2 years. Poor quality valve. Lifetime guarantee? They will charge you fifteen dollars to send you a new one. . . "Shipping and Handling" Brass does not tolerate heat. Typically, the maximum temperature is around 180-200 degrees Fahrenheit. The coolant temperature of a diesel engine is usually above this temperature. Stainless steel would be the best choice for proper coolant filter pack construction.