NX6010 suction side hydro leak

[justman777]

How long after start-up do you first notice a drop in performance?

If immediately, then begin confirming proper flow through the power beyond port by disconnecting it, and feeding the end that would go into the rear valve stack/three point into a bucket and measure flow and look for foaming on start-up.

I don't notice a performance drop right away, but I think that's because it takes a bit for the reservoir to fill up with aerated fluid. As soon as it reaches the bottom, I start getting bubbles flowing through the suction side.

I'll test the flow this afternoon. If the fluid is coming out foamed, I'll try bypassing the third function and see what I get.

 

[justman777]

I tried a few things today to see where I'm getting aerated fluid. To define aerated fluid, I see millions of tiny air bubbles in the fluid.

- Bypassed the third function entirely by putting the hose routing back to stock, and got aerated fluid in the reservoir. With the spraying it's doing from the top, I also get a good bit of foam in the reservoir. This means the third function isn't the cause of the aeration.

- Took the third function return hose and put it in a bucket. Got aerated fluid in the bucket. This means I'm getting aerated fluid through the third function.

- Took the third function supply hose from the power beyond port and put it in a bucket. Got aerated fluid in the bucket. This means I'm getting aerated fluid through the loader control valve.

- Took the loader control supply line off the loader control valve and stuck it in a funnel and then into a bucket (the hose is oriented up and doesn't bend easily). Got aerated fluid in the bucket. This means I'm getting aerated fluid up to the loader control valve.

I tried to be as systematic as possible, following the fluid supply line back towards the pump and removing components from the chain to eliminate them as potential aeration points. As far as I know, the next stop beyond the loader control is the pump itself.

Any ideas on where else to look?

I did notice that I didn't get any foam in the bucket like I did in the Reservoir. I'm thinking the aeration it's getting is exacerbated by having the fluid spray into the reservoir, which causes the foaming.

Flat out of ideas, short of waiting to hand it off to the dealer.

 

[TN8Man]

How long did it take for the aerated fluid to clear up back to non-aerated fluid in between your different configurations?

 

[DieselBound]

The original source of the problem could have been rectified but the pump has already been damaged, resulting in the same basic behavior of the original problem.

The strainer would absolutely be a good thing to check out. Cutting open a filter would also be worthwhile.

Here's an interesting article on hydraulic pump cavitation.

 

[justman777]

How long did it take for the aerated fluid to clear up back to non-aerated fluid in between your different configurations?

I took a break for dinner, and then came back and ran through the different configurations. I'm thinking it sat for at about an hour while I was inside. I only ran it for a few seconds in between tests, and it took me about 10-15 minutes to disconnect and reconnect hoses between tests. Each test pulled fluid from the reservoir and dumped into a bucket. The reservoir was clear of bubbles, best I could tell.

 

[justman777]

The original source of the problem could have been rectified but the pump has already been damaged, resulting in the same basic behavior of the original problem.

The strainer would absolutely be a good thing to check out. Cutting open a filter would also be worthwhile.

Here's an interesting article on hydraulic pump cavitation.

The pump could have been damaged, but the dealer changed it out the last time I took it in.

I checked out the strainer in the banjo bolt that feeds back into the reservoir from the loader control. Pretty interesting setup! The screen/strainer was clear as far as I could tell.

 

[xcgreene]

I don't have a manual handy, but where does the pump take suction from the sump? Is there an internal dipper tube with a screen on the suction line? With all of the troubleshooting you have done (which seems well done) it seems there is a considerable restriction in the suction, causing a much lower than usual pressure in that suction line, effectively boiling the oil due to the lower pressure (cavitation). Is there a way you can check the suction pressure, and compare that to typical suction pressure of the same type unit? This would let you know if there is a crushed dipper tube, or clogged suction screen in the sump, if there is one, or any type of restriction.

Also, I know that a number of these tractors hydraulic pumps take suction from the sump AND the power steering pump. Maybe there is something happening there?

This may have already been done, but I wanted to mention.

 

[YLee Kioti]

Any ideas on where else to look?

I did notice that I didn't get any foam in the bucket like I did in the Reservoir. I'm thinking the aeration it's getting is exacerbated by having the fluid spray into the reservoir, which causes the foaming.

Flat out of ideas, short of waiting to hand it off to the dealer.

The 2000 to 2003 7.3l Power Stroke had a similar issue. The fuel return was within 4 inches or so of fuel pick up. So the aerated return fuel was getting short cycled back into the fuel rails and adding to the famous diesel cackle. So you may be on to something that has merit.

The 7.3 issue had such a across the board issue some made kits to fix the issue.
Solution was to add a 24 inch line on the return side giving the return fuel time to be absorbed by the fuel in the tank. It did help some.

So, my Kioti dealer told me this was normal when I showed him my short video. With the occasional herky jerky and 3ph jump cycle, decided work was higher priority for me then letting him have it for weeks. Especially since the MLS valve was replaced, worked for a few weeks and then issue returned; albeit not as pronounced but there nonetheless.

The fact you have this issue and it is not a issue with the countless others seems/may(?) indicate there is a mfg. defect inside the casting of the hydro reservoir area?

No doubt it is frustrating trying to find the root cause.

Thanks for keeping us posted.....

 

[TN8Man]

My 5010 is worse. I not only get jerky pulsing 3 point but I also lose reverse movement intermittently when the hydro fluid is at max temp.

I did just look at the sump to pump pipe and the pipe is located near the bottom of the sump. Apparently no pickup tube, just gravity/suction fed.

Mine is heading to the shop in about 10 minutes, already loaded on the trailer.

 

[dusty3030]

My 5010 is worse. I not only get jerky pulsing 3 point but I also lose reverse movement intermittently when the hydro fluid is at max temp.

I did just look at the sump to pump pipe and the pipe is located near the bottom of the sump. Apparently no pickup tube, just gravity/suction fed.

Mine is heading to the shop in about 10 minutes, already loaded on the trailer.

Who is your dealer?