Class A RV maintenance Archives

Tiffin Allegro Bus Engine Coolant Leak Repair Guide (Cummins ISL 8.9L)

Drew Callahan · June 1, 2026

Tiffin Allegro Bus Engine Coolant Leak Repair Guide (Cummins ISL 8.9L)

Key Takeaways The Cummins ISL 8.9L engine in the Tiffin Allegro Bus has six primary coolant leak points: the water pump weep hole, coolant filter housing, EGR cooler, charge air cooler, hose connections, and freeze plugs.A cooling system pressure test…

Newmar Dutch Star Fuel Filter Replacement (Cummins ISL/ISB Guide)

Drew Callahan · May 29, 2026

Newmar Dutch Star Fuel Filter Replacement (Cummins ISL/ISB Guide)

Key Takeaways Newmar Dutch Star models (2016–2022) equipped with Cummins ISL 8.9L or ISB 6.7L engines require fuel filter replacement every 15,000–25,000 miles or annually, per Cummins service guidelines.The fuel system includes two serviceable filters: a primary fuel filter (secondary…