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How Do I Know if My Hydro Pump Is Bad of My Lawn Mower?

Hydro pumps are necessary to power a lawn mower. If the hydro pump is bad, the lawn mower will not start up. Many people are not aware of how they work or what affects them. 

Knowing this information might be helpful if you want to keep your mower running for longer.

A hydro pump is a mechanical source of power that converts mechanical power into hydraulic energy. It generates flow with enough power to overcome the pressure and is used in any lawn mower.

But this thing can become worse over time. Some of the main causes of the hydro pumps are interior leaks, exterior leaks, high-pitched whining sound, high temperatures, slow system performance, fluid contamination, and much more.

Hydro Pump of a lawn mower
Hydro Pump of a lawn mower

Symptoms of a bad Hydro pump

In this article, we’ll provide detailed information about the reasons behind a hydro pump becoming bad and possible fixes.

This happens when a hydraulic pump is bad in your lawn mower

Leaks inside the pump are often overlooked by people, but they can have devastating effects if left unnoticed. The most common cause of leaks is a loose seal valve. 

Leaks that are not fixed in time can lead to corrosion which further damages the pump. Leaks in a bad hydro pump can be caused by a break in the line too.

Excessive War and Tear

The excessive wear and tear of various components of a hydro pump is a major reason behind these leaks in the system. 

The surfaces of various components in a hydro pump are subject to wear and tear due to fluids, fluids reacting with the component surface which causes corrosion, etc. 

Poor Design and Incorrect Control tolerances

Poor design and incorrect control tolerances also contribute to these interior leaks.

Excessive clearances within the pumping mechanisms

Another cause of leaks in the pump is due to the bad hydro pump’s failure to seal the clearances within the pumping mechanisms. Excessive clearances within the pumping mechanisms can cause poor system performance. 

This is because the pump must work harder to overcome the leakage, and this results in more wear and tear on the pump. Interior leaks can be caused by several different factors such as poor quality, customer installation or contamination.

How to Fix Hydro Pump Internal Leaking 

Interior leaks are one of the most common problems with hydro pumps. If you can’t find out where the leak is coming from, make sure to fix the seal valve first. It could be that it’s loose or there’s a break in the line.

The best way to fix an interior leak in your hydro pump is by replacing the defective component. You can do this by turning off the electricity supply and turning off the water supply before you start work.

Some pumps also require periodic maintenance to make sure they are at their optimal performance. It’s important to get help from a professional for this task, but you can take care of smaller jobs like changing the gasket or tightening loose connections yourself.

A leaking hydro pump of a lawn mower
A leaking hydro pump of a lawn mower

Reasons of exterior leaks

If you have discovered liquid on the exterior of the pump, this means that the interior leak has worsened. Warning signs of a leak include bubbles, wet spots or unusual noises coming from your pump. 

If you are experiencing these problems, stop using immediately and call a service for repair. This happens due to failed seals in connections, hydraulic hoses, or pipes. 

A faulty installation or poor maintenance can also lead to these issues. A bad connection is a typical example of faulty installation. This is caused by corrosion on the connection fitting or by a loose threaded connection which is not tightened with enough torque. 

Other causes are shock & vibration, which can lead to the breaking of joints and cause exterior leaks.

If you notice any of these causes on your property, then you need to have a professional come out and fix it for you. When installing a new pump, you must take care not to over-tighten connections, hoses or pipes as this can cause leaks. 

You should also maintain your hydro pump so it will function optimally by checking for clogs and loose connections every year.

Noises are bad symptoms

Noises in a hydro pump can be the result of a variety of causes. It is important to identify and diagnose the cause of the noise in order to know what type of repair is needed. 

A high-pitched whining sound in a water pump indicates that there is a problem in the bearing or in the impeller shaft or other components. A bad bearing can be seen by checking for oil leakage. 

These will eventually lead to damage to other parts as well. A broken impeller shaft will lead to vibrations that are felt at all speeds and will also produce an unusual sound that should not be confused with other noises.

Sometimes noises came from a surging lawn mower engine also.

A loose drive belt cause sound

A loose drive belt can also cause annoying sound in the pump. If this is your problem, your next step would be to replace the faulty bearing or the broken impeller shaft with a new one of the same type and size.

A loose drive belt in lawn mower
A loose drive belt in lawn mower

High temperatures will damage the components

The effects of high temperature on the working environment of the hydro pump are not only simple. High temperature will produce a lot of wear and tear on the components in the hydro pump, which could ultimately lead to its death.

Over time, dirt and debris can build up in a pump causing a build-up of heat. To combat this, you should regularly check the condition of the pump and make sure there are no obstructions to airflow. 

It is also important to ensure that the hydraulic fluid temperature does not exceed 180°F because it may cause damage to components in your pump.

You should be able to identify obstructions to airflow by looking for signs like oily residue, leaks, or scales on heat exchanger tubes – all of which prevent air from flowing through your system.

Slow Performance issue

Is your system performance declining? There’s a chance your hydraulic pump is bad.

There are several causes of a slow performance of a hydro pump. One contributing factor for this is lack of efficiency which indicates a lack of flow and thus contamination from impurities such as silt, algae, and bacteria getting into the water. 

The other cause could be clogged filters due to material getting caught between them. The last cause could be high fluid temperature which will affect how fast it can turn turbines and create electricity.

Dangerous fluid contamination

Fluid contamination is the cause of many problems in hydraulic systems. It has been found that more than 75% of hydraulic system failures can be traced back to dangerous contamination levels in the hydraulic fluid.

Another vital cause of fluid contamination is corrosion, which occurs when metals break down over time. This corrosion forms acids that can contaminate the fluid and damage or destroy components.

When debris or moisture enters a hydraulic system, it can pollute the fluid and cause irreversible damage to the system.


Hydro pumps are an integral part of the modern lawn mower. They convert mechanical power into hydraulic energy. 

Hydro pumps can fail due to various reasons including mechanical issues, corrosion, and rusting, as well as lack of maintenance or carelessness on part of owner. 

In such cases, it’s important to understand what needs attention first before you take any action. In this article, we discussed about what a hydro pump is and how important it is for your lawn mower.

We also talked about how to fix it if it malfunctions so that you can keep your yard always looking great! Hope these will help you to get your hydro pump fixed. If you’re still experiencing this issue, we recommend that you contact our customer service team.

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