Same noise hear on a dk 4210. Did u ever get to the bottom of it or is it considered normal for the dk’s? Talked to the dealer and they said they had no noise complaints from customers.
Hey Cedar Fields. So I've been researching this a lot and think I finally have it all figured out. Thanks to Kioti Kyle on here that tipped me off to Facebook. If you search for the group "Kioti Tractors Group" on Facebook, request an invitation to be added. The search for posts containing "DK Pump Noise". There's a couple posts by gentleman named Curt and Mike on there that discuss the same problems. Curt shows photos of what his dealer found and how to fix it.
Apparently the 3 point lift valve in the case under your seat has an issue with the size of the return port (or bad casting?) and the hydraulic fluid "jets" out of it. When this happens it aerates the oil on it's way back to sump. Then as you're operating that aerated fluid goes through the pump and causes noise in the orbitrol steering valve. I was a little puzzled by this at first because the pump does not make any noise, and why wouldn't I have symptoms of air on the primary circuit? Well I paid closer attention and I do. If I run at operating speed for awhile and get it good an "aerated", and then operate the front end loader by lifting it, I can feel faint hesitations when it lifts as air is interrupting the lift. No noise though.
I have two dealers - the one I bought my machine from and the one that's closest to me. The closer has only been selling for Kioti's for a few years. They seem to have a lot of mechanical experience but have always told me they don't have any history of this noise (BS). The dealer I bought from is aware and so is the regional Kioti rep, but Kioti doesn't really have a fix for it. There is a service bulletin out there, but I later found it's not well known at the Kioti dealership level. The bulletin is just a Powerpoint doc (no bulletin #). It shows disconnecting the hose from the secondary side of the pump that goes to the steering valve, and adding an extra 8' of hose to the circuit to increase the volume. The folks on the Kioti Facebook group seem to say it has helped but not eliminate. I think this is a cheap way out for Kioti to try to solve some noise without solving the root cause. And my dealer wasn't super clear if this was covered under warranty because it's hit or miss if it works. I think the idea is having more fluid ahead of the valve maybe adds time for the air to disperse? Maybe break up into smaller bubbles that pass with less noise?
What is supposedly fixed it for one gentleman on Facebook was his dealer fabricated a piece of bent sheet metal that acts to diffuse the fluid to prevent all that turbulence that's causing the aeration as it drains to tank. He says it fixed all his problems. I showed my dealer this post, as they're rather interested in finding a fix for their customers. They shared with the Kioti rep and their response was "it was not an approved Kioti repair and wouldn't fix the problem". Frustrating as hell.
I also got some feedback that Kioti may have lost the casting design at one point in the production run, and had to re-create it, which may have resulted in this problem. And from I understand with the new DK20SE series (DK4220SE, etc) so far they haven't seen the problem.
If you search hydraulic aeration on Youtube, it's not good for the machine. Though with the pumps not making noise it's hard to tell if this will be a long term problem or not. Both dealers seem to tell me they have not had a hydraulic failure due to this specific issue. This model series came out in 2018. Unsure if all years up to the DK20SEs have the problem though. So if a failure does happen, guarantee it's after warranty.
I'm currently looking into a way to make a baffle plate, but I'm also going to have my dealer try to pull up part numbers for the 3 point lift valve I have and the ones on the DK20SE series. Interested if it's the same part #. Betting it's interchangeable. Probably several hundred dollars. Why should I have to pay for it though!
