By definition, a vacuum truck is a type of truck that is mounted with a vacuum tank loaded with materials using vacuum hoses. The tank has a pump that helps create a vacuum environment which enables sucking in of dry and wet materials for transport. To offload, the material is pumped out or the tank opened. Vacuum truck sales aim at making you understand the profitability of the truck. What most will not tell you is how it works. This knowledge however is very important and will help you know what to do in case something goes wrong.
A vacuum pump is fitted with several filters through which it pulls out the air from the tank. Air flow into or out of the tank is achieved by centrifugal force created by rotary veins which rub against the pump’s case. There are at least six of these veins in each pump depending on the model. From the final filter on the vacuum, the air passes through the primary shut-off and then the secondary shut-off. These shut-offs are made up of a cage that house a stainless steel ball and a rubber seat. The secondary shut-off should be drained often. 
The vacuum pump may be operated by a pump and motor combination (motor in the pump) or by relying on a Power Take Off (PTO) in which the power used to operate the pump is that relayed from the truck’s transmission by the PTO component.
To prevent the materials being transported from entering into the pump, the final filter has a fine screen. This ensures that the pump is not destroyed by the debri that reaches it. To help prevent destruction the pump needs to be cared for as per the manufacturer’s instructions. The recommended flush fluid should be used regularly to clean the veins and case. This flushing fluid is expelled from the pump and caught by an oil catcher muffler. This helps reduce the level of noise the truck produces when in operation. The catchers need to be emptied daily. Vacuum truck for sale.