Importing and modifying a new mini excavator from China

[ptsg]

Took a few pictures of the internal of my unit to compare to DFKRUG's ones in post #540. It has dual pump with the outboard stage going to what seems to be a priority flow diverter to the joysticks with integral safety solenoid valve and accumulator. Does anyone know what is the black threaded cylinder on the right? Could it be a filter?

It could very well be a filter for the pilot controls.

 

[dfkrug]

Took a few pictures of the internal of my unit to compare to DFKRUG's ones in post #540. It has dual pump with the outboard stage going to what seems to be a priority flow diverter to the joysticks with integral safety solenoid valve and accumulator. Does anyone know what is the black threaded cylinder on the right? Could it be a filter?

Besides the pump, you can see they also installed a blue safety solenoid valve to prevent operation of the tracks, blade and aux when the operator's console is up. That solenoid valve dumps the pump output straight back to the return line thus rendering the non-joystick spools non-functional.

The EM15 looks almost identical to the LeKing KV13Plus. Anyone know if LeKing is the actual OEM for the Diggit?

Welcome to TBN, Mike.

Very interesting changes to the EM15. Esp the separate aluminum valve block. The black cylinder may be a filter body, as PTSG says, or even an accumulator. You mention the latter....do you have a photo of the accumulator? Open up that cylinder and take a photo.

Looks like the the pump has two independent chambers, so no diverter/flow divider needed.

The bypass solenoid that disables the pressure side of the pump for some of the functions is a start, but it does not lock the affected functions. Good feature, and a step in the right direction.

There may be an inline return hyd filter. You have to look carefully under the floorboard.

Does the EM15 continue to be about the only unit like these with no hour meter?

 

[HCS-II]

Welcome to TBN, Mike.

Very interesting changes to the EM15. Esp the separate aluminum valve block. The black cylinder may be a filter body, as PTSG says, or even an accumulator. You mention the latter....do you have a photo of the accumulator? Open up that cylinder and take a photo.

Looks like the the pump has two independent chambers, so no diverter/flow divider needed.

The bypass solenoid that disables the pressure side of the pump for some of the functions is a start, but it does not lock the affected functions. Good feature, and a step in the right direction.

There may be an inline return hyd filter. You have to look carefully under the floorboard.

Does the EM15 continue to be about the only unit like these with no hour meter?

Thanks for the welcome!

Yep, still no hour meter standard on the unit.

The accumulator is there on the attached picture behind the flow diverting valve, just above the silver solenoid coil, on the left side. That valve body has both a solenoid and pressure relief valve on top...what would it be called in hydraulic's lingo?

The blue solenoid, located at the pump's output in the second picture, bypasses the first pump chamber back to return rendering both tracks and foot controls useless. The silver solenoid on the pilot control valving, in the picture attached, disables both pilot controls (joysticks) so all functions are disabled when the operator's console is in the up position.

There is a an intake screen in the tank but no return filter I could find. And I went through it with a fine tooth comb just to ensure no loose fittings anywhere. The only loose fittings I found where on the left-hand pilot control and on the right-side track motor. Also found a thinner o-ring on one of the aux line.

Mike

 

[dfkrug]

The accumulator is there on the attached picture behind the flow diverting valve, just above the silver solenoid coil, on the left side. That valve body has both a solenoid and pressure relief valve on top...what would it be called in hydraulic's lingo?

OK, I see the accumulator now. Now you gotta open up the cylinder on the right to verify it is a filter.

It is curious that there are 2 different torque proofing marks on some of the fittings. The latest in teal blue. And what are all those unused ports for? Maybe at least one is a pressure test port.

Nice to see some changes on the EM15. But no hour meter and no return filter, that's nuts.

 

[dfkrug]

Well, it has taken a couple of weeks, but I now have all the parts I need to install a double crossover relief valve (cushion valve) in the house rotation motor circuit.

Metric adapters and hose ends still seem to be tough to find in the US, and very high-priced. I used 4 different sources for these parts, as well as a few from my own collection.

Those of us who have lived JIC, NPT, ORB, and ORFS can get confused by all the variables in the metric world. There is DIN 2353, which is a tube standard used throughout Europe and Asia, but there are other metric standards that use O-rings. Photo is a DIN Light L08 M18x1.5 adapter (for both ports and 8mm tube) next to an M18x1.5 port O-ring metric adapter. Both same thread, but latter can not accommodate hoses with metric ends, as those use tube-style connections.

Not only are there confusing similar port/tube metric adapters, there are Light (L), extra light (LL), and heavy (S) versions. Don't buy the wrong one.

 

[ptsg]

Well, it has taken a couple of weeks, but I now have all the parts I need to install a double crossover relief valve (cushion valve) in the house rotation motor circuit.

Metric adapters and hose ends still seem to be tough to find in the US, and very high-priced. I used 4 different sources for these parts, as well as a few from my own collection.

Those of us who have lived JIC, NPT, ORB, and ORFS can get confused by all the variables in the metric world. There is DIN 2353, which is a tube standard used throughout Europe and Asia, but there are other metric standards that use O-rings. Photo is a DIN Light L08 M18x1.5 adapter (for both ports and 8mm tube) next to an M18x1.5 port O-ring metric adapter. Both same thread, but latter can not accommodate hoses with metric ends, as those use tube-style connections.

Not only are there confusing similar port/tube metric adapters, there are Light (L), extra light (LL), and heavy (S) versions. Don't buy the wrong one.

When these metric fittings are threaded into a port (valve, cylinder, etc), it uses either a copper washer or a dowty washer to do the sealing.

 

[dfkrug]

Here are my parts for the cushion valve project.

Other Chinese minis may use different size hoses or ports, so you still have to measure everything with a caliper. My philosophy is to convert hoses to ones with female JIC ends, then adapt to the required metric size. The hoses in this photo were standard 24" from SurplusCenter and only $12 each.

 

[dfkrug]

When these metric fittings are threaded into a port (valve, cylinder, etc), it uses either a copper washer or a dowty washer to do the sealing.

I know what you mean by the bonded washers. I have seen them, but did not know the name, Dowty. The one above uses a separate washer and O-ring, however. Are the adapters specced differently, O-ring vs. Dowty washer?

 

[Agitator]

Yes, of course, he should do that very easy test to see if they move separately.

It takes much more force to turn, vs drive straight. Small minis with 2-speed wheel motors often stall when trying to make a turn in high range. If RV setting was not verified, he may be starting with only 1500psi.

Sorry to take so long to reply - other stuff took my attention away from the mini-ex. But I do have an update - as I went to try to check on what the problem might be, I realized that the thing turns pretty well (one tread faster than the other, or treads running in opposite directions) if and only if the unit is still cold. Once I've been using it for a while, things heat up, and the drive motors lose power - including power for steeper inclines.

My unit is pretty much unmodified except for the addition of a tailpipe to vent the engine exhaust out from inside the house (it was directly under the seat, which made it pretty hot to sit on and actually would cause the gas in the tank to boil after an hour or so of use). it's this one from eBay, linked here.

I've been trying not to make any mods to the thing because I don't think that it's well-suited to my environment (it's just too hilly to be able to work it - I was using it in the morning on wet grass on the hillside for about 30 seconds before I decided that I didn't want to test the roll cage) and was planning on selling / trading it, so was hoping to avoid the kludged on oil cooler or weirdly-mounted engine compartment fan.

How would I check the pressure setting of the return valve?

 

[dfkrug]

I realized that the thing turns pretty well (one tread faster than the other, or treads running in opposite directions) if and only if the unit is still cold. Once I've been using it for a while, things heat up, and the drive motors lose power - including power for steeper inclines.

As the oil heats up, it gets thinner and more of it gets by clearances in your pump, and/or motors. This points to wear, likely caused by unfiltered or poorly-filtered hyd oil. On Utube there is a vid by The Garage Connection that shows a hyd pump from an Agrotk mini with significant wear at only 5-6 hours.

To adjust the main system RV, you can look at this vid, also quoted earlier in this thread: