View Full Version : Exmark hydro maintenance

Richard Martin
12-29-2001, 08:04 PM
I'm not sure about other brands of mowers but if you have an Exmark or Toro/Exmark ZTR you really do need to make sure you do the hydro system maintenance.

My buddy brought his Exmark over and we changed the filter and drained all of the fluid from the reservoir. His mower has 239 hours on it and it was bought new this year.

Just for kicks we cut the old filter open to see if there was anything inside of it.

We were amazed to see a lot of crud inside of the filter. It was actually caked up on the filter media.

I don't know if this is normal or not but it sure was scary looking. It was the dirtiest filter I have ever seen.

12-29-2001, 08:13 PM
must be doing it's job then. I would pobably look at his cap seal to make sure there is no debris getting in.

12-29-2001, 09:10 PM
I hope that wasn't the first time changing it.

Do it with in the first 50 hours, then at 500 hours.

If it was the first time, then there still was some lube left in the filter from when the hydro system was assembled.

12-30-2001, 12:51 PM
The owners manual says to change filter and fluid after initial 150 hours. Every 500 after that.

12-31-2001, 12:30 AM
Originally posted by LAWNGODFATHER

Do it with in the first 50 hours, then at 500 hours.

LGF, is the 50 hr change necessary? Have been running petroleum based systems up until last year but went closer to Exmark's service sched. (125hrs first change) for the TTHP.

"With eXmark hydros using Mobil 1®, you change the oil and filter after the first 250 hours, then only once a year. "

12-31-2001, 01:17 AM
That's what I've always done. Must work since I never had a hydro problem on my Exmarks.


Atlantic Lawn
12-31-2001, 07:34 AM
Check the seal on the cap,make sure that the seal is in good shape.I've never cut a filter open to know if "crud" build up is normal or not, sealed systems aren't suppose to be crud filled.Now I gotta cut one open to see.Thanks

12-31-2001, 10:46 PM
Ive changed mine several times on my Z and walkbehinds and the fluid always looked clean. I think next time ill do what Richards friend did just to see. Really there shouldn't be any gunk inside, ive rebuilt alot of hydro motors and have never seen any symptoms of wear other than the seals. You can change out the Lands on the motors the narrow lands run alot faster than the wide. Hydro motors should last many many yrs, ive seen them last for 18yrs with just 2 rebuilds. Marks Mowing Service

12-31-2001, 11:18 PM
If I recall correctly the hydro filter is a 1 micron filer, the fluid had better be clean going though that. And with it being in a sealed system, there should be no debris in it.

Richard Martin
01-01-2002, 09:35 AM
So there is no confusion regarding the proper filters and maintenance intervals for a 2001 23hp Kawasaki engined Lazer Z here is what the manual says.


2.8.5 Hydraulic Filter: Replaceable cartridge type.
P/N 1-513211: 10 microns, 18 psi bypass (Summer use above 32 F)
P/N 1-523541: 40 microns, 18 psi bypass (Winter use below 32 F)

5.1.26 Change hydraulic system filter:
Service Interval: After First 250 hrs.
Then yearly thereafter

This was copied directly from the Exmark owners manual that I downloaded from Exmark.

Premo Services
01-01-2002, 11:00 AM
The interval of changing the filters,is not the question, it is in the manual as richard has shown us. My question is, if it is a sealed system, and when you check the hydro oil, you wipe the top off carefully so no dirt gets inside, then where is all the dirt comming from?

01-02-2002, 12:58 AM
I kinda missed the 250 hr initial change by about 40 hrs. It broke my heart to see that perfectly clear Mobil 1 draining into the pan. I'm sure the filter had some trash in it though. I noticed the mower picked some of the original speed back up by changing the fluid. I guess it did have some trash in it.

01-03-2002, 07:46 PM
Originally posted by Premo Services
if it is a sealed system, and when you check the hydro oil, you wipe the top off carefully so no dirt gets inside, then where is all the dirt comming from?

Could be getting in from a loose or cracked seal on the filter. Check the level daily to see if any is seeping.

Here's the maint. recommendations from Exmark. Seems I have been changing fluids too often.

"Changing the fluid too often is not only not necessary but keep in mind that the only way to get contamination into a closed system is to open it to the environment. This can only be done if a hose is punctured, a hose is removed, a filter is removed or the reservoir cap is removed.

The filter is a 10-micron filter and will filter out any particles that are large enough to damage the internal components of the pumps or the wheel motors. That means the only other reason to change the fluid is due to contamination or thermal breakdown due to heat. The hydro system simply will not get hot enough to damage the fluid during normal use.

The fluid maintains its ability to lubricate so well that some operators don't even change the fluid. They just change the filter after the first 250 hours and then once every 1000 hours or annually after than. I don't generally recommend this practice because with a vented reservoir cap it is possible to get condensation in the hydro tank and water and Mobil 1 don't mix real well."