hydrostatic fluid change?

Gruneich Lawn Care Inc.

LawnSite Senior Member
I remember awhile back someone had posted the steps for chaning the hydrostatic fluid in my Exmarks, but I cant seem to find it? Anyone know were they went?



LawnSite Senior Member
SW Missouri
Simple. Clean around hydro filter and filler top. Remove filter.
Replace with new filter (filled with Mobil 1 15w-50).
Fill hydro tank.
Jack up back end of mower.
Run the mower forward and backward for about 5 minutes.
Check and fill hydro tank to top of baffle.
Run the mower until all air is worked out of the system.


LawnSite Member
On my ZTR I get the mower to operating temp remove the filter and then I have a suction too l(looks alot like a grease gun but made to suck) that draws the oil out of the tank then refill run it a bit then top off if needed.


Manufacturer / Sponsor
Good description accurate.

Pre-filling the filter is the most important step in changing the oil. If you don't you'll cause a large air pocket in the system which can be difficult to get out.

Here's what I do.

First I take my new EXMARK filter (pumps and wheel motors are expensive so don't chance damage by using non OEM filters) remove it from the packaging and fill it with Mobil 1 15W50 synthetic engine oil. Next place your drain pan under the filter. Remove the filter which drains the reservoir as well. Top off the new filter again and spin it into place. Fill the reservoir and let set for 15 minutes to allow the air bubbles to work their way to the top. Next top off the reservoir, replace the cap and go for a ride. It my wine and growl a little bit at first but if you've done everything correct it should drive well and the noise should decrease after 10-15 minutes of use.

Also make sure the top of the reservoir and cap are completely clean before taking the cap off.



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