What does a Vac Truck do?

Vac trucks are a specific type of machine designed for suctioning various liquids into their tank. Vac trucks are changing the face of excavation in South Australia and Victoria, thanks to their non-destructive methods.

Fleet of vacuum excavation trucks

What are Vac trucks used for?

A vacuum truck is used to suck liquids, slurry and sludge from a location into its tank. This allows the liquid to be transported to another location, either a soil transfer station or disposal site. Vac trucks were originally created to suction up high-pressure mining slurries and this is where the concept for vacuum excavation came from. The technology is still relatively new to the construction industry but is making waves thanks to its effectiveness on the job site.​​Vacuum trucks are fitted with high-pressure hoses and suction tubes, meaning they are capable of undertaking non-destructive excavation and vacuum clean up. Vac trucks are also used to empty tanks or bodies of liquid. This can include sewerage or septic tanks, water tanks and flooded areas. At VAC Group we are called to a range of jobs, from exposing utilities to emptying water treatment tanks.​

How does a Vac Truck work

A vac truck works by using a pump to create negative air pressure. Creating negative air pressure is, in basic terms, how suction works. However, depending on the power of the pump will depend on the strength of suction. This can be an important factor in the sale or hire of a vac truck as the pump will need to be capable of sucking a range of liquid materials.

In order for a vac truck to suction product, a suction hose will need to be attached to the pump and tank. These suction hoses are usually 3 inches in diameter and can range anywhere from a few metres long to up to 100 metres long. This allows vacuum trucks to complete vacuum excavation in tight fitting spaces, where even the truck will not fit.

If a vac truck undertakes vacuum excavation, there is normally a high-pressure hose also connected to the truck. One operator then uses the high-pressure hose to break down the material, whether it be soil, gravel or rock. Simultaneously another operator uses the suction hose to remove the slurry created.

What makes our VAC-U-Digga Truck different

Our Vac-U-Digga vac trucks are built in Queensland, Australia from local materials for rough Australian conditions. Our vac units include hydraulic systems, pressure systems and tanks, all made from Australian mild steel. By using Austalian mild steel we ensure our vac trucks can legally carry a full spoil tank and the mild steel will not rust at anywhere near the rate of heavier stainless steel.

Our vac truck cab and chassis are supplied by Fuso as their high quality product and design fit perfectly with our needs. Once the vac unit is created it is placed on the chassis and they are moulded together. Through this process we are able to customise the vac truck to the needs of our clients. Whether it be a more powerful pressure hose or extra long suction hose, we can accommodate it.

Typical uses for a Vac Truck

Vacuum excavation companies are most well known for their work with utility companies in locating their utility lines. This is because they are able to use their vac trucks to non-destructively dig for utilities and suction away the slurry that is left. This ensures that utilities aren’t damaged and avoids the risk of line strikes.

Vac trucks are also used regularly to clean and empty tanks, whether they be septic, water or sewerage. This is a task that is unique to the vac truck industry, as other methods of emptying tanks are not hygienically safe. By using vac trucks to safely suction the spoil into the tank it can be transferred to another location and disposed of appropriately.

How the VAC Group vacuum excavation process works

At VAC Group we do a lot of vacuum excavation, so much so that we’ve created a how-to video explaining our vacuum excavation process. Because we use inhouse Australian made machines we are able to complete a job faster and more efficiently than our competition.

Step 1: Pre-start check

Ensure everything is operational by doing visual and physical tests. Check things like the tires, the equipment and the pressure.

Step 2: Set up for the vacuum excavation job

Unwind the suction hose and pressure hose from the back of the vehicle and walk them to the job.

Step 3: Ensure one of the operators has the remote that controls the water

This remote turns the water on and off, controls the amount of water and the revs and idling.

Step 4: Transport the product is in the vac truck’s tank

Once all the product has been suctioned into the back of the truck it needs to be transported to a soil transfer station

Step 5: Unload the product into the soil transfer station

The product is then worked through the station and separated into dry soil and water.

Step 6: Reuse the water and soil at another vacuum excavation job

Contact VAC Group Today!

If you are looking for reliable vacuum excavation, utility location and non-destructive digging services in Brisbane, Sydney or Melbourne, give us a call. For more information on our vacuum trucks, click here.

Contact Us

  • Which state are you in?
  • Queensland
  • New South Wales
  • Victoria
  • Tasmania
  • Western Australia
  • South Australia
  • New Zealand

3000 Litre Hydro Excavation Unit

Our 3000 litre hydro excavation unit for hire is readily available for dispatch right across Australia. Find out more.

6000 Litre Hydro Excavation Unit

Our 6000 litre hydro excavation unit for hire is readily available for dispatch right across Australia. Find out more.


Our Hypervac 2+ and Hypervac 4+ non-destructive digging trucks are readily available for dispatch across Australia. Find out more.