DK40SE Squeal When Moving in Reverse.

[o2batsea]

I can see the advantage of a cab, especially while mowing a pasture and for snow clearing, but it doesn't make sense for everyone. My dealer wanted me to get a cab when I got my DK35 as he had one on the lot and would have given me a great deal.

But much of my work is brush hogging and wood gathering on very narrow, hilly, and winding trails. By now (after 52 hrs) I'm sure I would have at least managed to rip off one of the mirrors.

Mirrors on a tractor are about as useless any thing can be. Took mine off a long while back.

 

[mtr1950]

Computer back up and running so on to my update, Now own and have at home my new DK45SE HST with 72" FEL, have 6 hours on it and so far all normal and running well. Waiting for Brush Hog, Back Blade, and bucket teeth. Thinking about a Root Grapple, then back hoe. So far no squeal, I did not see the good idea posting about getting it in writting to take it back, but I will deal with it if it happens, from talking with other buyers(2 are my neighbors) dealer is trustworthy, and no squeal with them yet. Pictures as soon as I figure out how to post. Grapple I'm looking at is made by ANBO manufacturing. So far so good.

 

[IslandTractor]

Anbo makes nice but expensive grapples. Don't get one of their heavy duty models though as they are way more than needed for any CUT.

Search differences between clamshell and standard grapples. Mine is standard. Clamshell has significant differences some positive some negative.

 

[tnewbern]

Ok back to the task at hand. How many of you DKSE owners have pressure tested your HST. On a recommendation from Bob at Michigan Iron (Thanks for all your help) I performed the tests as per the service manual. I think I may have found something interesting.

My HST charge relief pressure is testing low. The manual calls for 255 PSI and mine tested 205 PSI. This starts at about 165 PSI @ idle and goes to 205 PSI @ 2000 RPM and holds thru full throttle. This was the same for both ports and consistent between tests. This was also the same after the machine runs for a while and the squeal is always present. Both high pressure reliefs tested fine and the squeal occurs way before relief. Its also different then the relief sound although the resonance is similar.

Here is what I think is happening. With low supply the HST is starved of fluid causing cavitation in the pump and/or motor. I believe this happens in both forward and reverse but we only here the resonance for the latter (different flow dynamics). If you pay close attention you can her some cavitation while moving forward but there is no resonance (squeal). This is more pronounced when the fluid is warm (thinner) or at lower RPM's (less flow).

The manual says to check for blockage but this squeal was there from day one. The 50 hours service did not fix this like Kioti hoped. Now after another 50 hours still no joy.

Did Kioti get a batch of bad, faulty or wrong charge relief valves? I don't see any adjustments in the manual. Its not the filters or fluid they have all been changed. Maybe there is an undersized, faulty or wrong hose, filter and/or fitting in the hydraulics. None of the other hydraulic circuits seem to effect the reading. I will let you all know what I find as I continue.

I was hoping the rest of you could pressure test your HST or have your dealer help and post your findings.

 

[mtr1950]

I will talk to my dealer about pressure test, put some more time on my machine today still no squeal. Island tractor how well does your Standard work on in the ground blackberry bushes? I like the look of the clamshell style for grabbing brush like blackberry, and lift logs, I have wood heat. ANBO is located in my state, I do like what they make.

 

[IslandTractor]

Island tractor how well does your Standard work on in the ground blackberry bushes? I like the look of the clamshell style for grabbing brush like blackberry, and lift logs, I have wood heat. ANBO is located in my state, I do like what they make.

I have really never run into a situation where I wished I had a clamshell. Lots of examples where a clamshell would not do as well mostly because that design is entirely dependent on hydraulic clamping to hold the load. Today I wanted to pickup three rocks in different places. Each was about the size of four inch thick large pizza. With my grapple I scooped the first, then the second and third before closing the upper jaw for transport. Each was held as if in the open upturned palm of your hand with the thumb just stabilizing the load. With a clamshell it would have been three trips or a juggling contest trying to get all three loaded. A clamshell works like your palm pointed down and using just the strength of your fingers and thumb to hold the load.
I scoop and hold huge loads of brush with no problem. Stumps, logs, branches, briar, no problem. Blackberry is like briar which i deal with regularly. I've posted lots of photos in grapple specific threads.

Anbo grapples are well made as they should be considering their cost. I have simply never found a situation where a standard grapple wasn't adequate. Mine cost $500 and is going strong five plus years later.

 

[Coyote machine]

This thread is supposed to be about squeal noises from DK-40 series tractors; it would be appreciated if we could move back to the original topic to keep consistency for those trying to solve this extremely annoying problem.

I will add one answer to a question I was asked about backhoe thumbs, earlier on in the thread; I have been offline so this is my first chance to respond.
I have a MIE backhoe thumb, as my signature indicates, from Michigan Iron and Equipment. It is NOT hydraulically operated, and I use it infrequently, thought it is up to the job of doing what it is designed for.
My answer to picking things up is an Igland GR-20 LOG grapple. I mention this because I have a LOT of trees, brush, stumps, etc to move, burn and deal with. It is compact: 36" wide x 42" max jaw opening, and it is very HD construction, for a total of 356# weight, so it will not adversely affect lift capacity of the loader.

The SQUEAL issue and a hydraulic valve not allowing proper flow dynamics after the fluid warms may very likely be the center of the problem for the affected tractors. How Kioti solves this problem is currently the question at hand; unfortunately there seems to be only quiet coming from them and no answers or response in general to this issue. If cavitation and other adverse effects are indeed occurring then the squeal is not just annoying it may also be doing damage to the tractors exhibiting its symptoms in the form of the squeal.

My tractor is going to the dealer, hopefully soon, to have the grapple's hydraulics installed, and a second rear remote valve to operate the jaw of the grapple; if Kioti ever gets its 'new 'puter' system running effectively!? I will ask about having the pressures tested for variation from normal.

I will make an attempt to get another video done of the squeal in my DK-40 that could be posted, possibly on You Tube, to reinforce the evidence that this problem is not isolated to one or just a few tractors.

 

[Coyote machine]

Spoke to my dealer about possibly testing the hydraulic relief valves and such. He says there is a way to test the hydraulic pump that supplies the rear remotes etc., but the HST is a separate pump and he does not know of a place to put a gauge to test its pressure(s), etc.

Any thoughts on this?

I do not know if there are in fact two different pumps for HST and other hydraulics- I am under the impression there is/was only one pump for all hydraulic fluids?!:confused2:

 

[o2batsea]

This thread is supposed to be about squeal noises from DK-40 series tractors; it would be appreciated if we could move back to the original topic to keep consistency for those trying to solve this extremely annoying problem.

I will add one answer to a question I was asked about backhoe thumbs, earlier on in the thread; I have been offline so this is my first chance to respond.
I have a MIE backhoe thumb, as my signature indicates, from Michigan Iron and Equipment. It is NOT hydraulically operated, and I use it infrequently, thought it is up to the job of doing what it is designed for.
My answer to picking things up is an Igland GR-20 LOG grapple. I mention this because I have a LOT of trees, brush, stumps, etc to move, burn and deal with. It is compact: 36" wide x 42" max jaw opening, and it is very HD construction, for a total of 356# weight, so it will not adversely affect lift capacity of the loader.

ROFLMAO!

 

[kattywumpus]

When Kioti visited last year to install the temporary fix they verified it wasn't related to hydraulic relief valves. For example: the rear remote relief value will trigger when the rear remote leveler is engaged and there is nothing is connected to the remotes or the connected hydraulic cylinder reaches the top or bottom of it’s stroke. It’s a very different sound and no where near as loud.

The hydraulic pump was replaced on my tractor which did no affect the squeal.

To review: the so called temporary fix was to replace the very short steel tube between the HST filter and the transmission with a longer flexible hydraulic line with two 90s at the mounting points. This helps to reduce the amplification of the noise or pulsation transmission through the HST precharge supply line. It also reduces fluid friction. At the time this was installed the Kioti engineers believed the sound was radiating for the HST precharge line and could be generating from the HST forward/reverse/neutral valve. There is another name for this valve but I do not remember it at this time. This is the valve the HST foot petals control.

 

[Coyote machine]

ROFLMAO!

I knew someone would pick up on the irony of my post

So KWumpass, If Kioti knows so much about what is NOT causing the squeal- do they know ANYTHING about what IS causing it?!

 

[tnewbern]

The HST pressure test is performed thru 2 ports located on the side of the unit (under the left floor deck). These ports are actually part of the neutral valves. The test is detailed in the service manual your dealer should know this.

Coyote Machine:
The tractor has a tandem hydraulic pump the first section powers the (FEL, 3PT hitch and implements) and the second (4WD, PTO, Steering and the HST).

Kattywumpus:
Did your dealer do a pressure test on your HST and what were the results. I was not implying it was the high pressure reliefs but rather the charge relief valve. The charge relief controls the fluid on the low pressure side. I am curious if the low readings I am getting are shared or local to my machine. If the HST is not getting enough fluid it will cavitate and make all sorts of noise.

I share your pain with the squeal. I am tired of people telling me HST transmissions make noise or I am not driving it right. I just want this fixed and if I have to get dirty then so be it.

 

[grsthegreat]

The HST pressure test is performed thru 2 ports located on the side of the unit (under the left floor deck). These ports are actually part of the neutral valves. The test is detailed in the service manual your dealer should know this.

Coyote Machine:
The tractor has a tandem hydraulic pump the first section powers the (FEL, 3PT hitch and implements) and the second (4WD, PTO, Steering and the HST).

Kattywumpus:
Did your dealer do a pressure test on your HST and what were the results. I was not implying it was the high pressure reliefs but rather the charge relief valve. The charge relief controls the fluid on the low pressure side. I am curious if the low readings I am getting are shared or local to my machine. If the HST is not getting enough fluid it will cavitate and make all sorts of noise.

I share your pain with the squeal. I am tired of people telling me HST transmissions make noise or I am not driving it right. I just want this fixed and if I have to get dirty then so be it.

geesh, if i had a pressure testing valve id go test mine and tell you the results. i do need to get one of these guages.

Page 5-22 of the service manual shows how to perform the test. seams easy. WAIT: the manual states neutral pressure is/should be 255 PSI but operating (driving) should be 4975 PSI. is this correct? nearly 5,000 pounds of pressure?

 

[grsthegreat]

Spoke to my dealer about possibly testing the hydraulic relief valves and such. He says there is a way to test the hydraulic pump that supplies the rear remotes etc., but the HST is a separate pump and he does not know of a place to put a gauge to test its pressure(s), etc.

Any thoughts on this?

I do not know if there are in fact two different pumps for HST and other hydraulics- I am under the impression there is/was only one pump for all hydraulic fluids?!:confused2:

According to my service manual page 5-22 the hose from the gage connects to the plug under the left floor deck.Looks to be right inside of the step. On my cab unit its just above the tool box.

 

[tnewbern]

Yes that is correct. You will either need 2 gauges a high pressure and a lower pressure or a digital gauge do you can get accurate reading for the charge pressure. You will also need an 7/16-20UNF adapter to connect to the test ports. The manual details both tests and you must be careful not to engage the HST while the low pressure gauge is connected.

My setup is a 5' 5000 PSI hose (burst is 20,000 PSI) with diagnostic quick coupler (not cheap). I got 2 gauges 0-6000 PSI and 0-500 PSI both with quick couplers. I got a 7/16-20UNF to 3/8 JNI but you can substitute for what ever is convenient to connect to your hose.

Today I bypassed the oil cooler with no joy (thinking it might be the restriction). I was able to test the pressure before the HST filter. This test setup is a bit trickier with the hard lines and all. The pressure here is much higher (over 250 PSI @ idle) indicating the filter may be the restriction for me. I am not say this is the problem as I have already changed the filter.

The low charge pressure may not even be related to the squeal but how can you look beyond an out of spec charge pressure. If you google HST charge pump and read you will see how important it is to a closed loop HST system. Here are some links to articles but there a many more.

Correct Charge Pressure Setting in Closed loop Transmissions

Hydrostatic transmissions

And this just for fun...

Troubleshooting Hydraulics

 

[dfkrug]

geesh, if i had a pressure testing valve id go test mine and tell you the results. i do need to get one of these guages.

Page 5-22 of the service manual shows how to perform the test. seams easy. WAIT: the manual states neutral pressure is/should be 255 PSI but operating (driving) should be 4975 PSI. is this correct? nearly 5,000 pounds of pressure?

I was just going to ask what the M24 HST pressure spec was. To put that in
perspective, my CK30 (M27) is only 4000psi, while my JD 4300 is 6000psi.

To do this test, you need to get a 10,000psi guage, unless you can find
one that is only 6 or 7K psi (less likely). There are 3 test ports, which are
readily accessible on tractors I have owned. They are for fwd, rev, and
charge pressure.

Note that some tractors have a separate charge pump for the HST (e.g.
my B21 did), or charge volume is provided from the PS pump (e.g. my
CK).

The HST relief valves are readily accessible on my CK, and the specs are
the same for F and R. Maybe the OP could swap the RVs on his DK to see
if it still squeals in reverse? At least that would rule out the RV as possibly
weak.

 

[Coyote machine]

Yes that is correct. You will either need 2 gauges a high pressure and a lower pressure or a digital gauge do you can get accurate reading for the charge pressure. You will also need an 7/16-20UNF adapter to connect to the test ports. The manual details both tests and you must be careful not to engage the HST while the low pressure gauge is connected.

My setup is a 5' 5000 PSI hose (burst is 20,000 PSI) with diagnostic quick coupler (not cheap). I got 2 gauges 0-6000 PSI and 0-500 PSI both with quick couplers. I got a 7/16-20UNF to 3/8 JNI but you can substitute for what ever is convenient to connect to your hose.

Today I bypassed the oil cooler with no joy (thinking it might be the restriction). I was able to test the pressure before the HST filter. This test setup is a bit trickier with the hard lines and all. The pressure here is much higher (over 250 PSI @ idle) indicating the filter may be the restriction for me. I am not say this is the problem as I have already changed the filter.

The low charge pressure may not even be related to the squeal but how can you look beyond an out of spec charge pressure. If you google HST charge pump and read you will see how important it is to a closed loop HST system. Here are some links to articles but there a many more.

Correct Charge Pressure Setting in Closed loop Transmissions

Hydrostatic transmissions

And this just for fun...

Troubleshooting Hydraulics

Good work! Thanks for the info and clarification about the split pump function, etc. I often feel as if my dealer speaks as if I am clueless, when I'm asking them to do things to solve problems?! It's as if they don't want anyone to know about anything but them- you know like its top secret or something like that! :confused2:

BTW, not bad for a jersey boy:thumbsup:

Keep the info coming. This thread is being viewed by many people, and we will prevail with Kioti eventually; even if I have to make it a personal mission.

 

[grsthegreat]

cool, ill check on some gauges, as they would be a handy thing to have around.

 

[grsthegreat]

Yes that is correct. You will either need 2 gauges a high pressure and a lower pressure or a digital gauge do you can get accurate reading for the charge pressure. You will also need an 7/16-20UNF adapter to connect to the test ports. The manual details both tests and you must be careful not to engage the HST while the low pressure gauge is connected.

My setup is a 5' 5000 PSI hose (burst is 20,000 PSI) with diagnostic quick coupler (not cheap). I got 2 gauges 0-6000 PSI and 0-500 PSI both with quick couplers. I got a 7/16-20UNF to 3/8 JNI but you can substitute for what ever is convenient to connect to your hose.

Today I bypassed the oil cooler with no joy (thinking it might be the restriction). I was able to test the pressure before the HST filter. This test setup is a bit trickier with the hard lines and all. The pressure here is much higher (over 250 PSI @ idle) indicating the filter may be the restriction for me. I am not say this is the problem as I have already changed the filter.

The low charge pressure may not even be related to the squeal but how can you look beyond an out of spec charge pressure. If you google HST charge pump and read you will see how important it is to a closed loop HST system. Here are some links to articles but there a many more.

Correct Charge Pressure Setting in Closed loop Transmissions

Hydrostatic transmissions

And this just for fun...

Troubleshooting Hydraulics

when you bypassed the cooler, did the squeal go away? you said the pressure went up

 

[tnewbern]

Sorry for the confusion.

No the squeal was still there and the HST charge pressure was the same. What I measured was the pressure before the filter.

You should get yourself a service manual. Check with your dealer they are about $100 or so. There is some good information in there and a bunch of stuff that should be in the owners manual.