There are many components to a hydroexcavator. It all begins with what makes first contact with the material you’re tackling on the job site — the boom. And the destination for that material is the debris tank. Here are some tips on how to properly maintain those two integral components that mark the beginning and end of the hydroexcavation process.

Boom inspection checklist

Prior to starting a job, inspect the hosing on the boom for any cuts or signs of wear. Also inspect the elbow of the boom.
“You’re looking for any holes, sandblasting or wear that is in that elbow,” says Mike Selby, national service manager for Vac-Con. “The idea behind all of this is that if you have any hole whatsoever, outside air can get in at that point and affect your vacuum.”

The elbow

The elbow is an especially high-wear part of the boom because it is at that point that the material being vacuumed goes from a vertical pathway to a horizontal one into the debris tank. Selby says many manufacturers will make padded wear plates to insert into the elbow.

“It’s a high-wear area, so that helps increase the amount of time the boom is usable,” he says. “I’d recommend operators check with the manufacturer of their machine and see if those types of high-abrasion-resistance components are available because every manufacturer does it differently.”

Grease the boom

In terms of regular boom maintenance, the keyword to remember is “grease.”

“Booms are pretty straightforward,” says Karl Roozeboom, manager of customer service and support at Ring-O-Matic. “Grease the points that need to be greased and that’s about it.

There isn’t a lot that can go wrong with a boom, other than just making sure everything is functional before going to a job. There’s nothing worse than getting out there and then the boom doesn’t work.”

If it’s a telescopic boom, every expansion joint where the boom extends will require lubrication, as will the mechanism that raises and lowers the boom and the rotator gear that moves it right and left.

“That’s one of the most used parts of the truck because that’s how you’re loading the truck — moving the boom up and down, and left and right,” Selby says. “That’s the workhorse of the truck.”

Rotator gear wear

An additional thing to look out for is any material that has accumulated in the rotator gear.

“It is a worm gear and ring gear assembly, so if there’s any rock or material that gets into the assembly, it can increase the wear time,” Selby says.

Avoiding damage to the boom

Outside of some regular greasing and cleaning, the boom requires little ongoing maintenance. Avoiding damaging it in a significant way then becomes another key in keeping it in good working order.

Roozeboom says operators should be aware of all overheads when raising and lowering the boom out in the field, for the equipment’s sake as well as safety. And before raising the tank, the boom should return to its seat.

“You could run the boom into the ground if it’s swung out the back and you raised the tank,” he says. “Or if the boom is up in the air, it could swing around in an uncontrolled fashion. Always return it to its seat before raising or lowering the tank.”

Clean regularly

The debris tank should be washed out after each application, no matter what kind of material is being vacuumed.

“It may not be hazardous as far as hazmat is concerned, but there may be some oils or other types of contaminants in the soil that you want to make sure don’t get passed on to another job or application,” says Selby. “So you have to clean the tank out regularly. One, it doesn’t cross-contaminate applications. And two, it makes your equipment last longer.

There’s no chance for any type of corrosion from material just sitting.”

The boom should be washed out periodically as well.

“The way these units work is that you have a vacuum generator evacuating air out of the tank faster than it’s capable of getting air in the tank. That’s how you create vacuum at the end of the hose,” he says. “So in order to maximize vacuum efficiency, you need to make sure the boom tube and the inlet to the debris body is free and clear of any material.”

Cleaning tips

With hydroexcavators, the cleaning process is easy thanks to the onboard high-pressure water.

“When you have your tank door open, just wash down the inside with a lance or whatever it is you need,” says Roozeboom.

He says operators can spray rust inhibitor on the inside of the tank to prevent corrosion, but it’s not vital. “It’s really not a huge issue because most of these tanks get enough usage that they don’t rust up. Just keep it clean. At the end of the day, wash it out.”

The same goes for the boom. Spray the onboard water up through the boom to ensure there’s a clear pathway from the tank to the end of the hose so that the vacuum can work effectively.

Shut-off valve ball

Roozeboom says it’s important to inspect the debris tank’s primary shut-off ball on a daily basis. “Make sure that the ball is loose and free inside of the cage and the seat that the ball goes into is clean.”

If that’s not the case, an operator runs the risk of overfilling the tank and damaging other components on the truck.

Other debris tank components

Inspect all seals on the tank to ensure they are clean and free of any material. It again goes back to optimizing the truck’s vacuum power, says Selby.

“Anytime air can get into that air stream, you’re going to have a drop in efficiency in your vacuum,” he says. “You want to be able to suck up all your air through the boom. You don’t want it coming from anywhere else on the truck.”

Keeping the seals clean also extends their life.

“If you have sand in between the seal and the sealing face, obviously it’s going to rub and it’s going to wear,” Selby says.

Also, make sure all grease points on the tank are properly lubricated.

“It’s either tilted with a single cylinder at the front of the tank or a scissor lift underneath the tank,” he says. “Either way, they have pivots that need to be lubricated as well as the hinge point that’s permanently fixed.”