01.003 Bus Cooling Systems: Simplified Maintenance Bus Cooling Systems: Simplified Program


This bulletin contains basic information on the use of Pencool® Supplemental Coolant Additive (SCA), in transit coach applications where a standardized, simple procedure is preferred. The following recommendation is consistent with warranty requirements.

Service Recommendation:

  1. Initial fill coolant: Use 50% Ethylene Glycol based low silicate, fully formulated coolant that meets ASTM D-6210 (ethylene glycol base) or ASTM D-6211 (propylene glycol base)
  2. Periodic maintenance:
    1. Pencool 3000 liquid program: Every 15,000 miles or 250 operating hours, add 1 pint of Pencool liquid for every 20 gallons of cooling system capacity, Pencool
    2. 3000 filter program: Replace the coolant filter with appropriate size Pencool 3000 filter. Always top off the cooling system with coolant consisting of 50% pure water and 50% antifreeze meeting ASTM D-6210 / D-6211 specifications. Never add pure antifreeze, water or automotive coolant to the coach!
  3. Observe Coolant Change intervals: Change the coolant per engine OEM recommendations (usually every two years or 200,000 to 240,000 miles, whichever comes first). Thoroughly clean the system, then refill with coolant as described above, in step I. It is possible to eliminate coolant change intervals by adopting a more sophisticated maintenance program. This program is known as Fill-For-Life®.