Power steering question/problem

[poor farmer logger]

Hi Everyone, just bought a slightly used Kioti DK35 HST with a cab. Been looking for a long time and come upon a deal that couldn't be passed up so we grabed it while we could.

Got it home On Wed. and have been running it off and on trying to get some tall grass knocked down with it.

Noticed a couple of problems though one was the squealing hydro while reversing but after allot of reading last night found out about a line replacement for it. The second problme though is with the power steering. When it warms up after running it for a half a hour or so the steering isn't as responsive as it should be or at least what I think it should be. If you are turning the steering wheel slow you can just keep on turning it. You have to turn it fairly fast and then when the wheels do turn if you let up on the steering they go back to center on thier own or close to. It's kind of a annoying thing. Is this normal on these tractors or a common problem? Seems like there is a valve that is bypassing somewhere and allowing the pressure to bleed off once it's warmed up.

Any help or ideas are appreciated. Haven't talked to the dealer yet due to the weekend but will be making a call. Should still be under warantee I would think. It's a 2010 with 170 hours on it now. Didn't buy it from the Kioti dealer but hopefully they are knowledgable with these tractors enough to help us out.

Thanks

Ryan

 

[oldnslo]

Does the steering wheel also turn back to center or just the tires turn?

If you turn the wheels to a hard stop does the steering wheel get harder turn? Both slowly and faster?

Roy

 

[poor farmer logger]

Hi Roy, the steering wheel does not turn back with the tires. If you turn the steering wheel really fast you can get the wheels to turn far enough that the relief valve kicks in but if you turn it slowly you can turn the steering wheel all day long and not really get any where.

Planning on getting a service manual for it so I can see what all they've got going on it there. Haven't tried to look under the hood or under the tractor to see what sort of valve they're using to divert oil to the wheels. Just thought I'd see if it was something that any other owners have ran into before.

Thanks

Ryan

 

[oldnslo]

Ryan,
Most power steerin gsystems consist of the steering valve or control taht is driven by the steering wheel and the steering cylinder. I am attaching a sectional view of a basic steering valve. This happens to be a Rexroth unit but, Eaton, Danfoss, etc. are of very similar design.

The steering valve controls how much oil is pumped or metered into the steering cylider by the geroter style pump built into them. This is the multilobed assembly on the right hand side of the picture.

The steering wheel is connected to the splines of the dark grey colored spool. The white "pin" is a leaf type spring that allows the light grey sleeve to rotate slightly independant of the internal dark grey spool. This slight movement directs the oil flow from the geroter to either the left or right steering port. If this outer sleeve gets sticky it can allow the wheels to drift and or alow oil to by-pass to tank at very little resistance. These valves are usually pretty robust but they are like any other made man item and do fail.

These are also a Real PITA to repair.

Bad cylinder seals could also cause some of the syptoms you are seeing. Cylinders can usually be diagnosed by turning the wheels to a hard stop and removing the return line from the cylinder and then checking for leakage flow past the seals by trying to turn the wheels against the stop.

 

[poor farmer logger]

Thank you for the info oldnslo, hadn't considered the posibillity of a interal leak in the steering cylenders but it is a possibility. I have a suspision it's a valve issue but you may be correct. If the tractor is sitting still the wheels will stay where you point them but as soon as you start moving they slowly come back to center. They don't always come completley back to center but usually pretty close. I haven't driven it on the road yet so I don't know how much of a hazzard it is there yet but it sure is a pain when working in tight spaces. Like the tractor so far otherwise though. Hopefully can get this problem sorted out.

Phoned the dealer this morning but they didn't know which way to go for sure. Wasn't till we mentioned a valve issue that he said yes it could be. Also didn't know anything about the reverse squeal and had never heard about the attenuator hose. Might have to just order that one and put it in myself as it may be more hassle then it's worth trying to get the dealer to diagnose it and agree to put it in under warantee . Hopefully that fixes that problem anyways.

Wanted to take a look at the tractor today and see how the steering was configured but didn't get a chance at all. Farming is taking priority now so the tractor may end up on the back burnner for a bit.

Thanks

Ryan

 

[poor farmer logger]

Just a quick update on tractor. Finally got the warranty transfered over to us and talked to one of the fellows from our local dealer and they're going to take a look at it once we can get it in to them. Had a bit of a let down when we got it transfered, it's a 2008 and not a 2010 like the dealer had sold it to us as. Wasn't from our local Kioti dealer. It was sold in August of 2010 though so there's still the 2 year power train left on it. The other waranty ran out on the 27th so he said even if the powertrain waranty didn't cover it they could put it under the other waranty because we had mentioned it before hand.

First little bit of combining today so not sure when we'll get time to get the tractor in to them though. His initial thought though is that the steering pump is shot. Also said it could be a cylender like oldnslo mentioned or posibly a bad valve. Reasureing to hear though that they're willing to work with us on it.

Ryan