What Is Cavitation?

Most jetter operators have felt cavitation but not realized what it is, or that there is a name for it. The machine suddenly sounds different, performance drops, and the hose does not seem to pull as well. Sometimes it feels like the machine is working harder while accomplishing a lot less.

That is cavitation.

In simple terms, cavitation happens when air is induced into the pump.

Think of it like trying to drink through a straw that has holes in it. You are working hard and getting nowhere.

What Does Cavitation Feel Like?

Operators describe cavitation as:

• Hose shaking
• Loss of pressure
• Increased vibration
• Pressure fluctuations
• Reduced cleaning performance
• A machine that suddenly sounds different
• A hose that does not seem to pull as well

If your sewer hose starts to shake, you may be inducing air into the high-pressure system.

What Causes Cavitation?

These are the most common issues:

• Dirty or clogged inlet filters
• Restricted water supply
• Collapsed or damaged supply hoses
• Air leaks in the water supply line
• Water tank issues that limit flow to the pump

In nearly every case, the pump is asking for more water than it is receiving.

Why It Matters

Any pump works best when supplied with a steady flow of water. Cavitation can reduce cleaning performance and make the hose difficult to control.

Harben’s radial piston diaphragm pump is built with true run-dry capability, but the system still needs a consistent water supply to perform at its best.

How to Fix Cavitation

It is usually easy to resolve. Start with this checklist:

1. Immediately shut off the pump.
2. Inspect and clean the inlet water filter.
3. Verify the tank is full and supplying water freely.
4. Check all supply hoses for leaks, collapse, or restrictions.
5. Inspect fittings and connections for air leaks.
6. Make sure the water level is above the pump to provide adequate head pressure. Then use the bleed screws to bleed the pump.

If you are leaking water while the machine is running, you are also pulling air into the system at the same location.

If none of these checks identifies the cause, the pump may need a full inspection and maintenance.

Cavitation Is More Hassle Than Crisis

Do not ignore it if your jetter starts shaking or vibrating more than usual, but do not assume the worst either.

The good news: most causes are simple to diagnose, quick to fix, and preventable with regular inspections and routine maintenance.

A few minutes spent checking your water supply can save hours of downtime later.