Chassis

Hydrovac bodies are typically mounted on Class 7 or Class 8 commercial truck chassis from manufacturers such as Kenworth, Peterbilt, Freightliner, Western Star, Mack, and International. The chassis must have sufficient gross vehicle weight rating (GVWR) to support the hydrovac body, water tank, debris tank contents, and all associated equipment within legal road weight limits.

Chassis configurations for hydrovac trucks include single rear axle, tandem rear axle, and tri-axle setups. Tandem axle is the most common because it provides a good balance of weight capacity and maneuverability. Tri-axle trucks can carry larger debris tanks and heavier loads but are longer and less maneuverable in tight job sites. Some manufacturers offer all-wheel-drive chassis options for off-road or challenging terrain access.

Key chassis specifications that affect hydrovac performance include engine horsepower and torque (which determine PTO power output), wheelbase (which affects turning radius), cab configuration (day cab versus sleeper for long-distance travel), and frame rail dimensions (which must accommodate the hydrovac body mounting). The chassis typically represents 30 to 40 percent of the total cost of a new hydrovac truck.