Two units with the same year and the same hours can be worth tens of thousands of dollars apart. These are the specifications and documents to ask a seller for before comparing hydrovac trucks on price.
- Debris tank and water capacity
- Tank size decides how long a crew works between dumps. Around 12 cubic yards of debris capacity with 1,300 gallons of fresh water is the common utility and daylighting spec; 15 cubic yards and 1,500 gallons or more pays for itself on pipeline work where the nearest dump site is an hour away.
- Blower airflow and vacuum
- Airflow in CFM and vacuum in inches of mercury set how deep and how fast the unit lifts spoil. Roughly 5,000 CFM from a positive displacement blower covers standard potholing; deeper digs and long hose runs want a higher rated blower. Ask when the blower was last rebuilt, not just what it is rated at.
- Water pump pressure and flow
- Cutting speed in hard clay comes from the water system: 10 GPM at 3,000 PSI is a typical utility spec. Confirm the pressure holds under load rather than reading it off a spec sheet.
- Cold weather package
- A boiler or hot box, heated valves and a tank heater are what make a hydrovac a year round truck. Without a working heat package the unit is a summer-only asset in any northern market, and retrofitting one is expensive.
- Boom reach, diameter and rotation
- Boom length, hose diameter and rotation arc decide what an operator reaches without repositioning the truck. An 8-inch boom at 27 feet with around 335 degrees of rotation is a common utility configuration.
- Chassis, axles and legal weight
- A full debris tank is heavy. Check the axle configuration and GVWR against the weight limits where the truck will actually work, because a tandem that is legal in one state runs overweight in another.