Dk45se weak hydro?

tractorsam · Mar 18, 2017

Hello,

This is my first post on TBN as I am having an issue with our new to us DK45se cab tractor. We previously had a CK35 which worked well but was too small and lacked AC. We also have several old Farmall tractors as well.

The DK has about 370 hours on it and is a 2010. We live on a steep hill and notice that in high range the tractor will stop moving forward and the engine rpm will only drop from 2500 to 2300 or so. Doing the same test in reverse the engine rpm will drop at least to 1600rpm. I'm thinking the forward relief valve may be weak. Where might I find this valve (if the tractor has one) and are there any pressure test ports? The tractor was recently serviced by a dealer and fluid appears to be full and clean. Any other thoughts on this issue are much appreciated.

Thanks, Sam

sdef · Mar 19, 2017

Can't help you with the HST issue. I test hydraulic pressure using the standard rear ports with this I made:

Btown · Mar 19, 2017

tractorsam said:
Hello,

This is my first post on TBN as I am having an issue with our new to us DK45se cab tractor. We previously had a CK35 which worked well but was too small and lacked AC. We also have several old Farmall tractors as well.

The DK has about 370 hours on it and is a 2010. We live on a steep hill and notice that in high range the tractor will stop moving forward and the engine rpm will only drop from 2500 to 2300 or so. Doing the same test in reverse the engine rpm will drop at least to 1600rpm. I'm thinking the forward relief valve may be weak. Where might I find this valve (if the tractor has one) and are there any pressure test ports? The tractor was recently serviced by a dealer and fluid appears to be full and clean. Any other thoughts on this issue are much appreciated.

Thanks, Sam

High gear is for driving long distances on relatively flat land. Hydro is not an automatic transmission. The more you push the pedal in the faster it will go., but it does not give it more fuel. When going up a hill if it starts to slow down you have to let off the HST pedal and or give it more throttle.

Thomas · Mar 19, 2017

As Btown wrote or lower range.

tractorsam · Mar 19, 2017

To the first poster - that looks like a great tester but I don't think the HST pressure can be read through the rear remotes.

I am familiar with hydrostatic drives as prior to the CK35 which was an HST we also had an IH hydro tractor (75hp hydrostatic drive) and I run into them a lot at work.

I understand that asking the tractor to climb the hill in high gear is probably too much for it although the CK35 would do it, as the engine started to bog down I'd start taking my foot off the pedal. My concern with this one is that it won't bog the engine down before the tractor stops moving.

If you try and start off on the hill at full throttle the engine will only slow a little bit and the tractor won't move. On the CK35 that would slow the engine way down or stall it.

k0ua · Mar 19, 2017

tractorsam said:
Hello,

This is my first post on TBN as I am having an issue with our new to us DK45se cab tractor. We previously had a CK35 which worked well but was too small and lacked AC. We also have several old Farmall tractors as well.

The DK has about 370 hours on it and is a 2010. We live on a steep hill and notice that in high range the tractor will stop moving forward and the engine rpm will only drop from 2500 to 2300 or so. Doing the same test in reverse the engine rpm will drop at least to 1600rpm. I'm thinking the forward relief valve may be weak. Where might I find this valve (if the tractor has one) and are there any pressure test ports? The tractor was recently serviced by a dealer and fluid appears to be full and clean. Any other thoughts on this issue are much appreciated.

Thanks, Sam

You may be correct about the relief valve, and yes there are test ports, and you will need a gauge that reads over 5000 PSI and you will need the service manual. BUT climbing any steep hill with your DK in HI gear is not advised. Especially with the extra weight of the cab. You are asking too much. Shift to MED and go up the hill. If your tractor engine is bogging in Reverse but not HI then perhaps the Relief is set low. But Really steep hills should bog down the tractor if in HI range.

ksbrdmkr · Mar 19, 2017

I road my DK45SEC for short distances and usually run about 2400 to 2500 rpm. When going up hills I wait to about 2000 rpm before clicking off the cruise to let the engine rev up. I am use to letting the torque rise of the lower rpm continue to pull without shifting. The torque rise of my NH TN55 keeps going up until below 1400 rpm, on the DK45 I think it is in the range of 1800rpm or so and the HST should allow you to pull the engine down to that range. When starting from a stop with a high load pushing the HST pedal down will bypass the HST or kill the engine.

Btown · Mar 19, 2017

There is a lot more weight in your DK than the Ck35. I'm not sure if your tires are loaded if they are it's even more weight. Try medium range. It should be plenty fast in medium. Hi is for long flat distances. If you still have a problem in medium then I would look into it. I do not know of any 75 hp HST tractors. I thought Kioti 60 hp was the largest HST tractor out there.

k0ua · Mar 19, 2017

Just for S's and G's, I tried My DK35se hydro today on my very steep hill.

I tried to start "mid hill" without getting a run at it. Here is what happened. In HI range going forward, I was not able to move, it just squalled and the hydro relief opened, the engine bogged some but the relief opened almost instantly. I pushed on the fwd pedal slowly.
Using the Reverse pedal and trying to go up the hill, it moved slowly whining like a 3 year old that you had just had his candy taken away, but when I tried to go a little faster and shoved the pedal down more the relief opened on the hydro also.

I had no problem going up the hill in Med range either forwards or in reverse. Which I commonly do when repairing this gravel road.

Here is how the tractor was equiped. It has the stock loader on it, and it had a lightweight rear scrape blade on the 3pt. I doubt it weighs more than 200 lbs. It is really too small for the tractor, and it was a left over from 2 tractors ago. The rear tires are loaded with Methanol mix. No cab.

Take aways. While my tractor is slightly smaller and has about 8 less HP and weighs a maybe a severl hundred pounds less in stock trim the tractors are near enough in size to test this. My key take away, is do not try to start on a steep hill in HI range. But I already knew that.