How to Change Hydraulic Fluid in Zero Turn Mower
When you notice that your zero-turn mower is losing power or steering, it may be due to a need for an oil change. There is no complicated step to follow, but things must be done in a specific order. Here are a few things you need to know before running to the store to pick up hydraulic fluid for your mower. We’ll examine how to change hydraulic oil on a zero-turn mower.
You can check over your Exmark mower and ensure it is in working condition by having your local Exmark dealer change your hydraulic fluids.
A dealer will inspect your starting system, safety switches, charging system, belts, and pulleys, among other things. Whenever you schedule your next maintenance, make sure you let them know you want to have your mower checked.
Please read on to learn what products you need and how to change hydraulic oil.
How to Change Hydraulic Fluid in Zero Turn Mower
It is not possible to service every hydraulic transmission. You must first find out whether your mower allows servicing. Commercial zero-turn mowers have modern hydraulic transmissions or hydrostatic drives that cannot be serviced and are usually sealed.
The most reliable advice is to look up your mower’s serial number and check to see if your hydrostatic drive can be serviced. Taking the next step depends on whether it can or not
The Exmark hydrostatic ground drive system is zero-turn
Depending on the model, Exmark zero turns use hydrostatic transmissions. A chart of the transmissions used in zero-turn vehicles is shown below.
| Model | Hydrostatic Drive System | Hydraulic Filter (Qty) | Hydraulic Oil |
| Quest S-Series | Hydro-Gear ZT-2200 | Exmark Premium Hydro Oil | |
| Radius E-Series | Hydro-Gear ZT-2800 | Hydro-Gear (2) | Exmark Premium Hydro Oil |
| Radius S-Series | Hydro-Gear ZT-3100 | Hydro-Gear (2) | Exmark Premium Hydro Oil |
| Radius S-Series Rear Discharge | Hydro-Gear ZT-3400 | Hydro-Gear (2) | Exmark Premium Hydro Oil |
| Radius X-Series | Hydro-Gear ZT-3400 | Hydro-Gear (2) | Exmark Premium Hydro Oil |
| Lazer Z E-Series | Parker Unitized Pump 12 cc & Wheel Motor System | Exmark Filter (2) | Exmark Premium Hydro Oil |
| Lazer Z S-Series | Parker Unitized Pump 12 cc & Wheel Motor System | Exmark Filter (2) | Exmark Premium Hydro Oil |
| Lazer Z X-Series | Parker Unitized Pump 16 cc & Wheel Motor System | Exmark Filter (2) | Exmark Premium Hydro Oil |
| Lazer Z Diesel | Kanzaki KPS-18T Trans 18cc Pumps & Hydro Gear HGM-18 Motors | Exmark Filter (2) | Exmark Premium Hydro Oil |
| Navigator | Hydro-Gear 12 cc Pumps, Hydro-Gear H Series Motors | Exmark Filter (1) | Exmark Premium Hydro Oil |
| Older Lazer Z Models: Lazer Z, Lazer Z HP, Lazer Z AS, Lazer Z CT | Exmark Filter (1) | Exmark Premium Hydro Oil | |
How to Change Hydraulic Fluid in a Zero-Turn
Manufacturers recommend different intervals between hydraulic fluid changes, but the general consensus is that the fluid should be changed around every 1200 hours of operation. Please check your owner’s manual first since I have seen shorter intervals.
Assuming your system has a fluid reservoir and dipstick, you must check it every 200 hours. Those who have an older machine should check the fluid reservoir every 50 hours. Again, it’s wise to verify these time intervals with your manual.
High-quality hydraulic fluid has a lifecycle of about five years. As soon as you reach five years old, even if you haven’t used your lawn mower much and haven’t reached servicing time, you should still change the fluid.
As well as replacing the fluid, you may notice some symptoms related to the hydraulic system. A lack of fluid in the system will cause partial or complete loss of drive, which will result in loss of drive.
The rear of the mower should be jacked up
Firstly, you will have to jack up the lawn mower. The rear wheels need to be at least three inches off the ground. You will then need a pair of jack stands to support the mower. Having the stand in place, you can then remove the jack to allow more workspace
Fill with Exmark Hydro Oil after removing the vent plug
There is a vent plug on every transaxle. You need to loosen the plug on each side. You will fill the expansion reservoir with hydro oil until it comes out of the vent plug at the end.
In the event that oil is leaking out of the vent plugs, adjust the vent plugs and tighten them. There is a small plastic tank on top of your mower’s seat that is the expansion reservoir for your watering system.
As soon as the plugs are tightened, proceed to add oil until the line on the expansion reservoir that shows the “full cold” level is reached.
The drain plug must be removed in order to drain
After this, you will want to locate the fluid drain plugs that are located on the bottom of each motor. If you do not have drain plugs, you can now proceed to remove the filter if you do not have drain plugs. If you do have a drain plug on your sprinkler head, you’ll have to unplug it so that the water can drain. Using your socket wrench, remove the plug from the drain plug in the catch pan and place it under the drain plug where the oil will discharge.
In order to remove air from the hydraulic system, it must be purified.
Firstly, it is very critical to remove all the air from the system by working through some steps with the drive tires turning freely while you do this. It is imperative to start your lawn mower and increase the throttle to the maximum. It is time to release the parking brake.
If you are planning to move the speed levers forward for a minute, make sure to push them all the way forward. Firstly, turn off your Exmark, let the hydros cool, and check the oil level in the hydros.
The fluid needs to be filled with new fluid
In order to complete the fluid change, brand-new oil must be put into the system to complete the process. Remove the filler cap from the reservoir and pour fluid into it with the help of a funnel. As a general practice, I recommend that you only fill it with 50% of the volume stated, and then check the vent plugs afterward.
In the event that the motors are full of fluid and they have pushed the air out of the vent enough to leak, the device will begin to drip. This is a reliable indication of the extent to which air has been removed. Therefore, keep checking the vents even as you fill the system, and when you notice a leak, stop the filling process.
