Lawn Mower Hydraulic Question

[marq]

Not sure this is the best forum but will give it a shot.

Have an MTD commercial 60" walk behind mower. The set up has the 17HP Kawasaki engine that drives a pump that feeds fluid to the drive pumps/hubs at each wheel.

I noticed toward the end of the season that one drive wheel would not turn as fast as the other. Even having the throttle on that drive pump/hub full open it was still going slow but then after a couple of minutes it would start operating normal and then run fine.

Entire hydraulic system was drained, refilled & new filter in the spring and ran fine for 4-5 months.

Would like to get some thoughts on what might be the issue so I can look into this before spring!

 

[oldnslo]

Slow speed indicates loss of flow. I would look at all of the linkage that changes speed & direction to see if some thing is binding when cool and then looses up or vibrates free under use.

 

[TMGT]

Also check the drive to the pump, I've seen belt slippage on one pump due to less then optimum belt routing combined with old belts or weak tensioner, even oil on the pulley.

 

[Rocky J]

Look to see if any of the plastic fan is broken on the slow side, this would allow for that side to get hot , if it is broken you will need a new one around $12 and another oil change , when the oil is a lot hotter then the air around the system it will condensate on the inside and make it milky. Do you use 20w50 synthetic oil ? Are they Hydro Gear brand ?