Hydraulic Issues 2020 CK3510

[SuperAwesomeDOOD]

Hello all,

I own a 2020 CK3510 HST with a factory backhoe. The hydraulics have never seemed adequate. Neither the FEL or the backhoe have the ability to perform multiple movements simultaneously.

Examples:

1. When operating the backhoe at the recommended rpm (1800-2200) it will not pivot to the side, exten the arm and dump the bucket at the same time. The opposite motion is also true. It won’t pivot back into the trench, lower the upper arm, extend the lower arm and open the bucket. Then when scraping the trench, it won’t curl in everything at the same time either.

2. When operating the loader, it won’t operate the lift arm and bucket tilt hydraulics at the same time.

It seems like my hydraulic pump is just not putting out adequate volume or pressure. The tractor sounds like it wants to stall with even the slightest incline in the mid range, and forget about the high range—it’s useless. I have to perform one action at a time and it makes normally fluid and efficient movements on other tractors feel choppy and inefficient on this one.

It also suffers from floppy bucket. Back dragging with the bucket will cause it to flatten before it “bottoms out”. I have to set the loader bucket down until it is actually pressing into the ground at the correct angle. If I just set it down, it’ll lose a few inches before the cylinder will hold my angle.

I know people will recommend taking it to the dealer since it’s under warranty, but if it’s a simple enough fix, I’d rather save that trek. I’m fairly rural. I’d at least like to know what to ask about at the dealer’s service department.

pretty sure it’s not fluid level, as it seems normal whenever checked. The tractor has about 80 hours on it. I had to replace some o-rings that blew under the seat around 30 hours.

 

[seville009]

I can only comment on the range issue. I have a MF1540 HST. High range is useless unless your just moving it down the road. I'm normally in mid range for traveling around the fields. Need to be in low range for any loader work or tall grass when mowing.

It's normal to not have full/fast functions when trying to do more than one function. If I want to move my bucket fast, I do it when stopped so it has use of the whole hydraulic system.

 

[K5lwq]

I don't think you have a problem with your tractor. The things you are describing are common issues with open center hydraulic system and HTS transmissions.

If the valve for your loader and backhoe has good metering, you can get it to do multiple functions but it will be slow. You have to feather the valve so not to rob the fluid from the other function. It will be faster to get use to one movement at a time.

Going up hill it is common for folks to use the hydro pedals like you would a car gas pedal and push harder down. Try reducing pressure on the pedal by lifting your foot a little as the engine loads up.

 

[SuperAwesomeDOOD]

The things you are describing are common issues with open center hydraulic system and HTS transmissions.

Is this due to it being hst or the control design? My 30-something year old Kubota can perform multiple functions quickly, but it’s a manual transmission.

 

[ptsg]

Is this a recent occurrence or has it been doing since new? Also, doesn't Kioti have a 50 hour service? Has this been done and with the right filters?

Three functions is asking a lot for this hydraulic system, however two is possible once the sweet spot is found, albeit a bit slower.

 

[K5lwq]

In a open center hydraulic system every thing is in series. This means when a valve is open upstream from another valve the downstream valve will be robbed of any fluid.

Some valves are better than others at feathering making it easier to do two functions at the same time. Then there is a few valves that have a parallel and series circuit to allow for multiple functions at the same time. But in order for these type valves to work well it requires a higher flow pump or the movements will be very slow.

At 11 GPM you are going to be limited.

 

[TMGT]

Is this due to it being hst or the control design? My 30-something year old Kubota can perform multiple functions quickly, but it’s a manual transmission.

It would be due to the control design, the HST is a separate system from the implements (only shares the fluid).

I have found that Kubota's seem to have better loader valves then some other companies, at least in the compact market, they will allow easy multifunction movements.

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[TMGT]

In a open center hydraulic system every thing is in series. This means when a valve is open upstream from another valve the downstream valve will be robbed of any fluid.

Some valves are better than others at feathering making it easier to do two functions at the same time. Then there is a few valves that have a parallel and series circuit to allow for multiple functions at the same time. But in order for these type valves to work well it requires a higher flow pump or the movements will be very slow.

At 11 GPM you are going to be limited.

It only has a little over 7gpm to the implements, the Kubota TLB's, B and larger, actually have a separate pump for the boom. My experience with compact BH's you can get 2 functions depending on what they are, maybe 3, but takes a lot of effort to maintain smooth control.

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[SuperAwesomeDOOD]

Is this a recent occurrence or has it been doing since new? Also, doesn't Kioti have a 50 hour service? Has this been done and with the right filters?

The performance of the hydraulic system has always been a bit underwhelming. Not a new occurrence. Yes, the 50 hour has been completed.

At 11 GPM you are going to be limited.

Are there upgrades that can be made to the pump?

I have found that Kubota's seem to have better loader valves then some other companies, at least in the compact market, they will allow easy multifunction movements.

Are there aftermarket valves for the backhoe that perform better? I can get over the loader’s performance.

 

[TMGT]

There are aftermarket valves available, but I doubt you'd gain much if anything and would require adapting it and trying to tune it. Most OE's use various valve sections depending on what function it is controlling, along with restrictors. I'm not sure your experience with these type of BH's, but I would talk to the dealer about it, and if everything was operating correctly then just practice feathering the functions until it works as well as you can get it.
It's also possible to add restrictors to help slow flow to some functions.

I built my own BH with a monoblock valve, it works well but it can still be a chore to balance multiple functions, even after doing some tuning using restrictors.


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