The BB-4^® Diesel unit is a high-pressure fire pump that has been used by forest agencies for Type 6 brush trucks. The BB-4^® Diesel comes in a horizontal pump drive mount as standard with a vertical drive mount optional. It is powered by the Kubota D902 Super Mini-Series 3-cylinder liquid cooled diesel engine.

The BB-4^® Diesel has been officially listed on the USFS Type 6 Fire Apparatus specifications. It pairs a high performance 4-stage centrifugal pump end with a powerful 25 HP Kubota diesel engine. Its interchangeable pump end with the legendary MARK-3^® allows for in-field exchanges eliminating long equipment down time and greatly reducing parts inventory at service shops. When building your next wildland fire engine, choose the name that wildland firefighters trust the most: WATERAX.