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Danger of a Dry Starting a Hydraulic Motor

Did you know you can invalidate the warranty of your final drive motor if you make the mistake of dry starting it after you’ve just installed it? Read on to learn what a dry start it, how it can damage your motor, and how to keep it from happening to you.

Danger of a Dry Starting a Hydraulic Motor

Here are a few additional posts you might be interested in ...

What Does Dry Start Mean?

To dry start a final drive motor means to start it without sufficient hydraulic oil in the hydraulic side of the motor, but it could also refer to starting the final drive without enough gear oil in the planetary side of the motor.

The Misconception Behind Dry Starting

Many people mistakenly believe that because hydraulic fluid circulates through the hydraulic system that all you need to do is connect the hoses to the right ports and you’re good to go. Just because the hydraulic fluid circulates doesn’t mean you can attach an empty component and expect it to be ready to run. And frankly, there is no excuse for dry starting the planetary side of a final drive motor because there is no circulation of fluid to fall back on.

What Happens When You Dry Start

When you dry start a hydraulic motor, there is not enough oil in either side of the hydraulic motor (hydraulic side or planetary side). That means that the components like gears, bearings, pistons, and shafts will not have sufficient lubrication. That means you’ll have metal grinding on metal, which can damage critical surfaces, leaving abrasion, scratches, and (in worst-case scenarios) gouges.

That damage can lead to flakes and other tiny bits of metal breaking free and contaminating the hydraulic fluid or oil once it has access to these parts. Then you have contaminated hydraulic fluid, which can cause damage before it is trapped in a filter.

Scratches and abrasions lead to a reduction in performance, which means that a brand new final drive motor ends up with compromised efficiency and power from the start. In short, you’ve damaged the motor immediately after installation, and dry start damage is not covered by warranties.

Avoiding a Dry Start

Before starting a hydraulic motor that is either brand new, repaired, or rebuilt, add clean, new hydraulic fluid to the hydraulic hub and make sure there is fresh gear oil in the planetary hub. That is all you need to do in order to avoid a dry start.


Just a few simple steps can help you avoid damaging your final drive hydraulic motor by dry starting it. Since damage caused by a dry start is not covered by warranty, it is all the more important that you make sure your motor has fluid and gear oil before you start it.

Texas Final Drive is your partner in providing new or remanufactured final drive hydraulic motors from a single mini-excavator to a fleet of heavy equipment. Call today so we can find the right final drive or hydraulic component for you, or check out our online store to find your O.E.M. manufacturer brand motor now. 

Visit the Final Drive Shop for all of your hydraulic final drive motor needs!

Final Drive Motor Overheating Gearbox Troubleshooter Guide (Free Infographic)

Topics: Final Drive Motors, Gear oil, Final Drive Installation, Warranty, hydraulic fluid

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