Hyd Pump brand

[rScotty]

Why would it not affect steering if it's a common suction causing the problem. That theory holds no water in my book. I'm betting he has a tired pump section, probably due to some sort of issue way back in time. Like a remote valve or three point control stuck on and gone un noticed for a bit too long. Maybe just normal use but a LOT of it. Who knows, but the flow meter is the proof. Anything less is just a guessing game.

I admit I am guessing. We don't have a choice yet. So far we don't have a flowmeter and the OP hasn't found anyone who does. Also, the OP has not posted his hydraulic schematic - and until he does we can't know for sure how his tractor is plumbed.
I don't think that shouldn't keep us from speculating. Speculation is fun and also a good way to learn..

Whether a suction air leak would affect steering or not depends of whether the two pumps are using a common suction circuit or two independent ones. You assume they are common; I assume the pumps have separate suction circuits. The argument for common is simplicity, but if so why use two pumps?
I chose independent suction circuits because to me that is the best way to design for what the tractor needs to do.

I think of it this way: It is far more expensive to build two pumps - even given that they have a common drive - than to do the same thing the other way, which is to build one pump and then feed its output into an inexpensive diverter valve to divide the flow into two separate flows post-pump.

So there must be advantages to go to the complexity and expense of two pumps. The advantages I see are twofold: to make the steering system more failure proof and to keep one downstream circuit demand from stealing all the flow from the other. The best way to do both of those is to make it so that both pumps have their own independent suction path to their own dedicated input port.

I assume that the Kioti is that sophisticated partly because that is the way that other tractors are made.

rScotty

 

[BackRoad]

Respectfully, you two guys are amazing...simply amazing!!!

 

[Harry in Ky]

I admit I am guessing. We don't have a choice yet. So far we don't have a flowmeter and the OP hasn't found anyone who does. Also, the OP has not posted his hydraulic schematic - and until he does we can't know for sure how his tractor is plumbed.
I don't think that shouldn't keep us from speculating. Speculation is fun and also a good way to learn..

Whether a suction air leak would affect steering or not depends of whether the two pumps are using a common suction circuit or two independent ones. You assume they are common; I assume the pumps have separate suction circuits. The argument for common is simplicity, but if so why use two pumps?
I chose independent suction circuits because to me that is the best way to design for what the tractor needs to do.

I think of it this way: It is far more expensive to build two pumps - even given that they have a common drive - than to do the same thing the other way, which is to build one pump and then feed its output into an inexpensive diverter valve to divide the flow into two separate flows post-pump.

So there must be advantages to go to the complexity and expense of two pumps. The advantages I see are twofold: to make the steering system more failure proof and to keep one downstream circuit demand from stealing all the flow from the other. The best way to do both of those is to make it so that both pumps have their own independent suction path to their own dedicated input port.

I assume that the Kioti is that sophisticated partly because that is the way that other tractors are made.

rScotty

If you look at the parts breakdown for this model you can see very quickly how the pump and lines are laid out. It will answer many of your questions and narrow down your speculations.

 

[rScotty]

Respectfully, you two guys are amazing...simply amazing!!!

Luckily, there are a number of guys on TBN who know hydraulics well enough to enjoy helping.
It's also a good way to learn more and get involved with interesting problems - all without tracking oil into our own workshop. The downside is that too often we don't get to hear how it turned out.

Right now I think we've hit the "how it works" part hard enough for a start.
I'm curious to see what the OP decides to do.

rScotty

 

[NYlumberman]

I’m not so sure that a leak on the suction side of the pump would be oil temperature sensitive. That fact sends me toward a valve seat or a spring. I had a Gresen bank of valves with crack in one valve body that made me look stupid for a week before I finally found while replacing the whole 4 valve assembly. All education is expensive.

That said the advice on establishing pressure and flow is spot on.

 

[rScotty]

I’m not so sure that a leak on the suction side of the pump would be oil temperature sensitive. That fact sends me toward a valve seat or a spring. I had a Gresen bank of valves with crack in one valve body that made me look stupid for a week before I finally found while replacing the whole 4 valve assembly. All education is expensive.

That said the advice on establishing pressure and flow is spot on.

I don't think we know if oil temperature has anything to do with the problem. The problem might be just from running and completely independent of temperature.

 

[Fracture]

Thanks for all your input. Yes, it's a 2-part pump. I did a thermal check. The 2 sections of the pump are only 3-5 Celsius different (54C & 49C), while inlet tube was 42-46 C on average. Outlet tubes temps were about what was on the respective pump side. I'll post schematics ASAP. I'm working through holiday weekend, so it may be a minute. I think I'll look for Cat (or similar) shop to get flow tests done for starters. I'm always up to learn new mechanics and I may wind up going this way if I can't find help locally. I'd love to not go back to my dealer, but unfortunately, they're the only place to get OEM parts.

 

[oldnslo]

Fracture
Were you operating the loader when you performed the temperature test? If yes my guess is the pump is fine and problem is elsewhere. If pump is slipping so much nothing moves it will heat up fairly quickly.

 

[Harry in Ky]

And so we have another opinion here. Maybe someday we'll find out what the problem was.

 

[Fracture]

While I'm in my a search for equipment mechanic, here's my schematics if anyone thinks they can help. Checked temps with surface reader, but wasn't directly running FEL (or any other hydraulics). Pulled into barn and only running at idle.Had just used tractor with FEL/PTO. It was warm, but not at the point where it usually poops out. Just didn't have time or need for heavy use that at the moment. I'll recheck after an hour of heavier use asap.