DK45 HST steering pump rebuild/replace option?

[Msamt]

I remember reading the owners manual, warning me to not use the rear remote lever without anything connected.
I remember someone here telling me to put a male to male hose between the remotes, just in case.
I remember reading about removing the detent balls, just in case.
I remember someone here saying their shorts hit the remote lever when they jumped off the tractor to pick up a stick.

I remember jumping off my tractor to pick up a stick, when I was mowing yesterday, but since I had my Remington ear shot protectors on I did not notice anything at all. Never got the hose, never removed the detent balls, and of course I was mowing in long shorts (it was 85 degrees).

For 20 minutes everything was fine.

It Started with not being able to turn to the left unless I spun it hard. Then to the right. Then I got scared and parked it.

Went in for a drink of water, pulled up TBN and read about the same thing happening when the remote gets stuck and deadheads.

After some frantic PMs (thanks James!) to a few on here and elsewhere, I realized it is not the same pump as what drives the tractor. I mowed with it today, after resetting the remote lever, fluid looked fine, smelled fine, ran fine, but still was a squirrelly, I assume I cooked something.

MIE lists the pump for $1160, and it looks easy enough to swap out, anyone know if there is a rebuild option, or rebuild service somewhere?
It looks like only one side is for the steering and the loader and 3ph is on the other, so maybe their?

Any other option? No binding on the tires, it just needs a fast spin, which after reading through the threads it seems that is a key indicator.

This is the parts diagram from MIE

Anything other to try?
Thanks!
MT

 

[Agvg]

Dead end a pump in a normal circuit should not do much more then burn diesel and generate heat. Are you sure there not are a priority valve that connects both pumps?

 

[xcgreene]

Best I can find is this. But has no part numbers.


Kiotis own workshop manual says to replace the steering unit if there is internal leakage.

Having said that, 20 minutes does not seem long enough to heatsoak the system to the point of steering unit failure, especially with an HST tractor that is underway, as oil is still going through the cooler. Sure the relief valve at the joystick was working overtime because the remotes were engaged


Assuming you have already confirmed your oil level is good,
* The modulator valve could be leaking back to the tank, Does the 4wd and PTO still engage correctly and quickly?
* The sequence, or reducing valve inside the modulator could also be faulty/dirty, causing this.
* There is also a chance that the steering relief valve is stuck open.
* A filter change may also be a cheap try.

Here a reference for the modulator valve to help you identify these valves.



Just some things to try. I hope it works out alright for you.

 

[Msamt]

Dead end a pump in a normal circuit should not do much more then burn diesel and generate heat. Are you sure there not are a priority valve that connects both pumps?

The post from xcgreene shows the modulator and sequencing valve, I think that’s where I check first.
MT

 

[Msamt]

Best I can find is this. But has no part numbers.
View attachment 563510

Assuming you have already confirmed your oil level is good,
* The modulator valve could be leaking back to the tank, Does the 4wd and PTO still engage correctly and quickly?
* The sequence, or reducing valve inside the modulator could also be faulty/dirty, causing this.
* There is also a chance that the steering relief valve is stuck open.
* A filter change may also be a cheap try.

Here a reference for the modulator valve to help you identify these valves.
View attachment 563511


Just some things to try. I hope it works out alright for you.

Thanks a ton, this helps, the pto and 4wd engaged fine and the hydro level was fine, ill start with the modulator valve, then. Move onto a filter, due anyway. And maybe replace the fluid.

MT

 

[Agvg]

Yes, you have two separate pumps so you don't have that valve I was talking about, is it still bad? Have you tried to lift the front and turn the steering back and fourth, the only thing I can think of is oil foam so you have gotten air in to the steering system, the valve you dead ended are on the other pump.

 

[Msamt]

Here’s a question. How is the reducing valve or sequence valve removed? It appears they are threaded in from the picture from the manual Can anyone verify?
From noodling over the theory of operation as I understand it (barely), it appears these two are the best places to start, should I remove the entire modulator block first or leave it bolted up?
Assuming release pressure with the tractor off, remove valve, inspect, replace seals if necessary and or replace valves as necessary.
Replace filter and fluid (11 gallons iirc)


Thanks!
MT

 

[Harry in Ky]

In your first post you mentioned the tractor wouldn't turn unless you "spun it hard". What did you mean by that? Did the steering wheel take more effort to turn, or the same effort but more/faster movement? One would indicate a pressure/flow problem, the other leads more toward steering cylinder internal leakage.

 

[Msamt]

In your first post you mentioned the tractor wouldn't turn unless you "spun it hard". What did you mean by that? Did the steering wheel take more effort to turn, or the same effort but more/faster movement? One would indicate a pressure/flow problem, the other leads more toward steering cylinder internal leakage.

Same pressure, but had to turn it faster, more often to start it turning.

MT

 

[Harry in Ky]

I'd be looking more at steering cylinder than pump related problems.