Signs Your Hydroexcavator is Running into Trouble

There are certain warning signs you should pay attention to when it comes to pumps and blowers
Signs Your Hydroexcavator is Running into Trouble

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Even with proper maintenance being performed on equipment, problems can still creep up. That includes on hydroexcavator blowers and pumps, which is why contractors need to keep their eyes and ears open for warning signs of larger problems.


According to industry experts, the most common problems with pumps are low pressure and cavitation. Low pressure is exactly what it sounds like — the pump doesn’t have adequate pressure to do the job. Vac-Con service manager Mike Selby says low pressure can be caused by worn valves, pump packing or poor drive condition.

If the water pump pulsates, that’s another sign of trouble, says Randy Johnson, president of GAP Pollution and Environmental Control in Johnstown, Pennsylvania. Cavitation, where the hose jumps violently making it difficult for the operator to control the wand’s water spray, is caused by bad water pump check valves, suction leaks and blocked filters.

If the pump stops working in cold weather, Selby says there’s a good possibility a pipe has frozen. There are several options to help prevent that from happening, including the use of a heated collar on decant valves, using a glycol injection system to keep pockets of water from freezing, and filling the truck the night before a job and then keeping it in a heated garage. If the truck is kept outside, drain all of the truck’s water and leave the valves open.


When it comes to blowers, improper pressure around blower points is an issue contractors may be able to catch before it becomes a problem. “Too much carryover causes wear on blower lobes,” Selby says. “The material can wear away at the rotating parts and render the blower incapable of moving enough air to convey material.”

Signs that indicate a possible problem with the blower include excessive noise, inability to achieve full vacuum or the blower getting hot.

Contractors should run their equipment at a speed just high enough to complete the work they’re doing. “By running the truck too high, you can cause problems such as overloading your filters and damaging your blower, wasting fuel and bypassing water that can wear pump parts,” Johnson says.

Another sign that something may be wrong with the blower is a dust plume coming through the blower exhaust. That could be a sign the filter cartridge or baghouse filter is clogged and may need to be replaced or was improperly installed.

If the blower’s cartridge filter is wet, Johnson says it could mean several things, including the velocity in the pick-up hose being too high or the debris tank and cyclone being full of liquid. Another possibility is that the primary separator has failed or a gasket has become loose.


Selby says contractors should have their hydroexcavators serviced by a professional if they notice burn marks by the blower.

Those marks are caused by heat and can indicate insufficient airflow causing ultra-high vacuum and damage to the rotating parts, he says.


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