DK40SE HST - Loss of speed after 50 hour service

freewookie · Jan 10, 2014

After completing the 50 hr service I've noticed a loss of speed. I've topped off hydraulic fluid, checked for leaks, etc. Hydraulic fluid level is about in the middle.

Haven't done in loader or PTO work so can't say if there's a loss of power too. Weather will be nice this weekend so I will soon.

Thoughts?

Thx

MotorSeven · Jan 11, 2014

What type of hydro fluid did you use, premium or regular?

VictorW · Jan 11, 2014

The weight of fluid may be the problem. Most of the fluids Kioti reccommends are a 10W-30 multi-weight hydraulic fluid. If your weather is cold now, a heavier weight fluid may not flow as well until the fluid has warmed up. The system is self bleeding so any air caught in places from drain and then refill should purged.

freewookie · Jan 11, 2014

I used the TSC premium fluid but it was probably only a gal to top off. Dealer recommended against changing the fluid, only filter.

VictorW · Jan 11, 2014

Members here have used TSC premium fluid for complete changes with no problems so topping off shouldn't have made a difference. I have no clue why new filters only would cause this problem. With an HST, you should have changed two filters. One is just for the HST which is bigger and has a larger threaded hole for I believe more flow and one is for the rest of the hydraulic functions. They are both different in mounting so you can't interchange them. Maybe another call to the dealer is needed.

SSdoxie · Jan 11, 2014

Possibly the hydraulic filter (suction filter) is not tight allowing air to draw into the system? If you have done any loader work, the loader may cycle fine with no load but would show signs of weak or jerky movement under load if there was aerated oil. Look at the hydraulic filter you took off and make sure the rubber gasket came off with it. Not uncommon for the gasket to stick to the filter base and stay in there especially when changing the original filter when 3 men and small boy with a 10' cheater put it on there. :laughing:

freewookie · Jan 11, 2014

Unfortunately it's been three or four weeks since I did it so the filters are long gone. I did a little loader work and pulled 800 -1000 lbs of logs on a trailer. Didn't sneeze at any of it. I put a bit more fluid in to take it close to the top notch on the dipstick.

MotorSeven · Jan 12, 2014

How much speed are we talking? I had a similar experience and had used regular hyd fluid, so I dumped it all & re-filled with premium. I think I get 11mph out of it on a flat surface in high gear & it has been that way for a long time. I never GPS'd it the first year I had it, but it did seem faster back then.

Amvcane · Jan 12, 2014

I have a brand new ck35hst that had to be split to fix a leak and it came back with the forward speeds slower but reverse seemed faster. Called dealer and he said the treadle is attached with two bolts and it is adjustable. Looking from the side of the tractor if the treadle is leaning forward at rest it will hit the floorboard before it is full speed forward and reverse may be faster. I loosened bolts and tipped the treadle back tightened bolts, and all was fine. It should be adjusted so when the treadle bottoms out in the tractor case it will hit the floorboard at the same time. Hope this helps.

freewookie · Jan 12, 2014

Had the wife follow me down the driveway today. I was hitting 7-8 mph in medium which is within the range. Maybe I'm just going nuts for the weather.

I'm also going to check the pedal adjustment too.