DK40SE Squeal When Moving in Reverse.

[robiefield]

Apologies.

I was wringing hands over my inability to find a useful Kioti parts resource online so I could look up and order a recessed shaft banjo bolt without waiting. I figured for ten-twelve bucks it would be worth an unverified shot at knocking the problem down, and an addition to the collection of troubleshooting documentation if it didn't work out.

I think I got ahead of myself.

After re-reading this thread, I understand that Tom in NJ is waiting for a recessed shaft banjo bolt to arrive from Kioti. And that Tom plans to verify the proposed solution before presenting it as such.

I don't want to ruin my welcome right after it's been given. I'm gonna sit tight and wait for Tom to share more after his parts order comes in.

 

[dourobob]

I think I got ahead of myself.

I think we are all anxious , but right now, I believe Tom is the MAN and waiting for his (consistently) detailed diagnosis will be good for all of us who have "squealers".

Working on improving my patience
Bob

 

[Coyote machine]

robiefield,
I hear all of what you said and believe me you are not the only one wanting Kioti to put up some reference material for us owners, and something called a CD or DVD of owner's manuals, shop manuals with available updates, service bulletins, etc., to be at least available to search for anyone who wants to do so. I mean what's the down side- are we likely to go rogue and replace our dealers and buy all parts and service everything?! Not possible, even off warranty.

I've suggested this to Kioti in NC and the response was the usual cookie cutter answer: Oh thanks so much- we'll pass it along...

BANJO BOLT(S): My dealer said he thinks that if the original design was the long bolt with tapered shaft that it might have been breaking due to not having a lot of strength in that particular length, with the hole through the bolt's shaft and the hole through it's center. Consequently, they may have redesigned what bolt was used and attempted to allow for adequate flow in the actual banjo fitting's trough, INSTEAD of tapering the bolt shaft to accommodate the needed flow.
Maybe he is aware of something that we as consumers aren't privy too, or don't have the proper security clearance to be trusted with- but I think his process is not valid- for my own reasons.

He also states that if Kioti changed something like a particular bolt type,:confused2: for whatever reason then all prior bolts of another type would have been sold off or discarded?!
Now I was born at night, but it wasn't last night!:laughing: That is a complete crock, IMHO.

I also want to test the theoretically correct, (longer bolt with shaft taper) ASAP because everyday i'm out pounding away the hours my machine AND my ears are suffering the consequences.

I'd also like to know how Tnewbern is able to get the part numbers, etc. without some backdoor connection to Kioti parts diagrams/ etc. Is that too much to ask for a clean and totally straightforward up front approach?

CM out

P.S. I managed to get TBN admin to change the title of this post to read correctly- especially since so many people are reading it- it makes sense to have the title correct... agreed?!

 

[grsthegreat]

Kioti has a parts manual, a service manual and the owners manual. I own all but the parts manual; however i recently purchased one and I'm awaiting its delivery. that part number has to be in that manual. The service manual shows the part, but not the corresponding number.

 

[dourobob]

Kioti has a parts manual, a service manual and the owners manual. I own all but the parts manual; however i recently purchased one and I'm awaiting its delivery. that part number has to be in that manual. The service manual shows the part, but not the corresponding number.

I am fairly new at the parts manual look-up but, as I see it, on Page 197, it seems that the bolt is either #21 or # 22 on the diagram which are parts #T4620-37092 called a "JOINT BOLT" and T 4520-90042 called a "BOLT, JOINT".

Hope that helps.

My scanner is not working right now to post pics (also copyright issues??)

Bob

 

[tnewbern]

You are assumeing the squeal is the problem. The squeal is only a symptom and the wrong one to focus on. The bolt fix may soothe the pain but the trouble is still there. Until I get a chance to follow up on the details I will say only one more thing.

Check your charge pressures!!!

I bet you find they are off spec. This includes you to kattaywumpus. Your tech may not have disclosed this to you but follow his trail its right on.

I don't have time for details now but keep checking in.

 

[grsthegreat]

You are assumeing the squeal is the problem. The squeal is only a symptom and the wrong one to focus on. The bolt fix may soothe the pain but the trouble is still there. Until I get a chance to follow up on the details I will say only one more thing.

Check your charge pressures!!!

I bet you find they are off spec. This includes you to kattaywumpus. Your tech may not have disclosed this to you but follow his trail its right on.

I don't have time for details now but keep checking in.

he said the fix caused his pressures to fall back into the normal range. and the squeal is gone. seems to me like its the fix.

 

[Coyote machine]

You are assumeing the squeal is the problem. The squeal is only a symptom and the wrong one to focus on. The bolt fix may soothe the pain but the trouble is still there. Until I get a chance to follow up on the details I will say only one more thing.

Check your charge pressures!!!

I bet you find they are off spec. This includes you to kattaywumpus. Your tech may not have disclosed this to you but follow his trail its right on.

I don't have time for details now but keep checking in.

FWIW, my dealer took a look at your post about the power steering pressures being too high at 450psi and said: that is NOT too high.

I don't see why if the squeal disappears a problem still exists, according to your thinking.
Why can't squeal being gone = problem solved?
Take the time to explain your reasoning - we're all capable of understanding whatever the explanation may be, and frankly the be patient routine is wearing thin- we're dealing with damage to expensive pieces of machinery here.

 

[tnewbern]

Hey grsthegreat I know what I said when I found the bolt and hastily checked my pressures. The squeal is gone that is for sure over 15 hours of work in 80+ degrees not a single squeal. There are other noises though that concern me the major one is singing and mostly in forward. The artist sounds vaguely familiar to the squealer. There is absolutly less restriction without the banjo bolt in question. I can't tell you the difference the other bolt will make until I receive it. I am waiting just as all of us for it to arrive.

CM backoff there is nothing I can do. I do not have any special connection with Kioti. Call your dealer and order a banjo bolt. I ordered the one that is on the bottom of the HST filter. That is all that was needed they can lookup the part number and I don't know what it is. You can also get yourself some M18 fittings and make up a bypass hose as desribed earlier and shown by kattywumpus (thanks for the details and images).

Now I don't think the bolt is the real problem. This is a restriction in the system and not good but this is not why my (I say my because none of you have tested yours) HST is low on charge pressure. Removing a restiction improves the flow and the supply to the HST precharge. In addition to reducing flow this restriction could also cause an oscillation (squeal or noise) in the lines.

The output of the power steering is the low pressure flow that supplies the HST precharge. Maybe your dealer thinks you mean the output of the power steering control valve to the steering cylinders. In a perfect systems this pressure should be identical to the HST precharge pressure (255 PSI). Any restrictions will add back pressure and 200+ PSI is almost 2x not what I want to see (that is one big oil heater).

We bring them a tractor and say there is an annoying squeal which I'll admit is subjective. They start up the tractor and mash the pedel down ... nope no squeal. After much debate you show it to them and how to reproduce it. You must be doing something wrong. The squeal is subjective and easily deniable. Finally you convince someone and they go to work and try and fix the squeal. The amplitude and frequency of occurence starts off low but as we all know grows to even the slightest touch of the reverse pedel. How many service departments are going to take that much time?

If you bring your tractor in and say the charge relief pressure is low this is easily measured and verified. This is an objective problem there is no denying a measurement. Well I guess Kioti could issure an ECO thats modifies the value to say 205 PSI (that would be a huge mistake). Now you can't do this if you don't actually measure your tractor and know its low for sure.

Ok so let me try and explain the real problem without all the details. Your HST is a closed loop variable displacement pump and motor circuit. This circuit requires makeup oil to replace losses while operating. These losses vary depending on load and use. This is the flow in question and is controllerd by the charge relief valve. This valve should be closed until the pressure builds to 255 PSI. Once this happens the valve opens and passes the flow to the HSY case. Once the case fills with oil it overflows into the transmission and gears and back to the tank. If the relieve valve never fully closes then the pressure will only build to the remaining restriction. This leaves the HST with a reduced supply of fluid and under load conditions the HST can starve and cavitate. Just read through the desriptions in the "Service Manual". There are several places that identify low charge pressure with noise and a faulty or stuck charge relief valve. There is one problom though this valve is buried in the HST requires splitting the tractor and HST to examine (not good).

I suspect Kioti knows this (not sure about our dealers they may be on the darkside of the moon with the rest of us). Kioti is trying to find a solution that does not hurt them. Tearing all these tractors down to fix the charge relief valve is a major hit to their margin. If they can improve flow maybe it will be good enough for us to go away (for now). After all we are not complaining about the charge pressure its the squeal. I suspect they found the banjo bolt restriction as did I and hoped it would do just that. Now for what ever reason they chose to change the hard line out entirely. Maybe this improves flow that much better. Maybe they did not consider just the bolt. By the way I have a larger hose and fittings than kattywumpus in my bypass maybe that accounts for the differing results. I won't know for sure until the parts arrive and hense the reason for delaying the solution or partial solution.

From what I have heard I am sure Kioti will back us but we need to bring them the real problem. They are not going to do extra work if they don't have to. All they need to do is nurse this along till the warrenty expires. This is not hard considereing the hours most of us put on the tractors per year.

Tom

 

[kattywumpus]

Tom,
If the engine is idling should the charge pressure still build to 255 psi if the HST is not in use? Is this high enough RPMs for the pump to build the pressure? I'm wondering for testing purpose. It seem to me if the charge pressure relief valve is work correctly the pressure will still build.

I'm starting to wonder if Kioti knew what the issue was all along, since when I first reported the issue Kioti kept tell the dealer and myself that I needed to run the engine at least 2600 RPMs. It seem to me running the engine at this RPM resulted in greater charge flow and pressure in an attempt to overcome a restriction in the charge circuit or issue with the charge pressure relief valve.

Plus I been wondering why Kioti give me an extra HST oil filter block and mention replacing the hard line between the charge line cooler and filter block. Original the engineer stated it was because the block is aluminum and the thread are easily stripped. I thought it was an interesting offer since I had not planned to make any tractor modification myself. I wanted Kioti to fix the issue not waste my time troubleshooting. How I wonder if that filter block is different from the one in my tractor.