small Chinese Excavator repairs

[dfkrug]

I have now had my Rhinoceros (Xiniu) XN08 for nearly 6y, imported from China in 2018. My main TBN thread so far has been about importing it, and modifying it to do what I want, and not get damaged:

Importing and modifying a new mini excavator from China

It has been a while since I posted a Big Project on TBN, so here we go again. I have been on a quest for a mini-X, so I imported a new one from China. It has been complicated and took a lot of time and energy, but it is here and working. Over the next week or so, I will post about my search...

www.tractorbynet.com

I have been building and widening my trails on my mountainous 19 acres, as well as stacking up logs for future splitting or milling. I am only at about 150 hours, and I have had just a few repairs. Mostly, I have modified it, from installing my own gasoline engine, to fabricating oil and air cooling systems, to installing protection from damage.

I want to use this thread to post repairs, especially if there are photos and tips/tricks learned from experience. Not just my repairs, but repairs other small non-name-brand excavator owners have done. I have seen some photos on Utube and here on TBN of failures that I have not experienced. I welcome those people who have had those failures to post here about their experience. Specifically, I have heard of failures to the rear wheel supports, the house hyd motor and pinion gear, the wheel motors, and the blade cylinder support. Maybe there are ways to avoid those problems.

 

[dfkrug]

When I first got my machine, the factory replaced any faulty parts I had under their one-year warranty. I had one poorly-crimped hose, and a damaged seal on one of the valves in my main stack. The parts came quickly by air, though the hose replacement required access inside the house, up on my mountainside. That required removal of the ROPS, console, valve levers, and floor.

Since then, the only repairs have been minor, and all hydraulic.

Here I had to replace one of the blade cylinder hoses. Fortunately, I had a spare, but it was longer; a bit too long. The original hose gets pulled pretty tightly when the blade is fully down, and that pinched a small rock under the hose. Now, the new hose sticks out further to the side, which is also not ideal. Hose length is important! Now I have a protection plate.

If the tracks are on, the connection for this hose is very hard to access. I used this 17mm crows foot wrench that I ground down to fit. If your tracks are off, it would be good to check this hose for tightness.

If you buy hoses with metric (DIN light) crimps, make sure your O-rings are there and in good shape, I had to get new O-rings for mine.

 

[dfkrug]

Here is another repair I did years ago. When my mini was new, I found one of the grease zerks did not take grease. I checked the zerk, which was fine, but the plain bearing insert grease hole did not align. So I removed the zerk, drilled thru the bearing insert, and reinstalled the zerk.. In this photo, I show how I changed from needle greaser fittings to zerks, plus I rotated the rod cross-tube so the zerk was underneath, and protected.

BTW, these yellow replaceable bearing inserts look just like the ones on my JD 4300 tractor. Nice.

 

[Sonny580]

I want to replace the nasty needle zerks on my L-12 if possible-------- HATE them nasty needle things! lol!

 

[drawthree]

I want to replace the nasty needle zerks on my L-12 if possible-------- HATE them nasty needle things! lol!

When I first saw them I hated them too, but that was before I tried to actually use them. When I actually gave them a try I was shocked at how well they worked.

 

[dfkrug]

When I first saw them I hated them too, but that was before I tried to actually use them. When I actually gave them a try I was shocked at how well they worked.

Yeah, they do work. Biggest reason to change for me is I use only one grease gun (Lincoln, battery-powered) with a locking nipple-grabber on the end. Works great, and I do not want multiple messy guns.

 

[Sonny580]

Same here--- one old STANDARD gun --- use it on everything!!

 

[dfkrug]

These next 2 repairs involve hydraulic cylinders. Overall, I am impressed with the quality of materials used, and both repairs were not due to poor assembly, construction, or materials. The rod finish does not rust readily, as often occurs with lesser units.

When the container of 6 black 1T minis came from Ouke via Alibaba in 2017, the shipper wrapped them with a bunch of that clear plastic film that is often used with palletized goods in warehouses. I don't have Before pix, but one of the units had some film tightly wrapped around one of the cylinder rods. Then the cylinder was operated and the film got pulled into the gland.

To fix it, I had to disassemble the cylinder.

I have done many different kinds of cylinders. This one uses a retaining ring, like a lot of JD loaders. It came apart easily, but the piston nut was welded on!. I have never seen that before.

The piston uses dual cup seals and a rub-ring, which were in perfect shape.

 

[P708]

Greetings TBN!

I cannot hold my enthusiasm any longer. Having spent many years extracting amazing ideas from such great minds on TBN, I decided to dive deeper into the abyss and see what lies beneath.

Last month, I purchased a brand new AGT DM12-C excavator.

My previous machines were varied, including a Harbor Freight Trencher, a Kubota B6100D with backhoe, and Jinma 284 with backhoe, so I was familiar with Chinese technology, and I was always excited to understand everything there was to know about each machine. My 20-year-old Harbor Freight trencher, which I still have and it’s a great one-man party, and paid for itself several times over!

Now, a new challenge: The DM12!

My 17-year-old Son and I drove to Washougal Washington and he drove the DM12 onto the trailer there, and once home, drove it off and parked it. I finally got to drive it and moved it about 20 feet to my shop [lesson one-don’t do a 180 on your lawn] and I began the exciting process of getting to know my new ‘Big Boy toy”, or maybe its a Mini Big Boy Toy, or sub-compact toy, or whatever anyone wants to call it!

Starting at the bucket, I worked my way back to the rear engine cover in a couple of weeks. I am very pleased with the overall construction, robust framing and the decent workmanship that went into this machine. Far better than the Jinma.

I have incorporated some of the MODS offered by TBN members, and added a few of my own. I hope to glean and share information as I go along.

So far, at 70+ years of age, I have been successful in life; Like the badge- Veni Vidi Vici, [I came, I saw, I conquered] I intend to do so with my DM12.

I look forward to my, or rather ‘our’ adventures.

 

[drawthree]

I have incorporated some of the MODS offered by TBN members, and added a few of my own. I hope to glean and share information as I go along.

What mods have you done? Any pictures you can share?

 

[dfkrug]

I have incorporated some of the MODS offered by TBN members, and added a few of my own. I hope to glean and share information as I go along

You are welcome to add pix and info about modifications to the modifications thread. Link in post #1.

 

[P708]

What mods have you done? Any pictures you can share?

First thing I noticed, was on the lower arm. The actuator rod clevis had three brass needle type, flush lube fittings. Each one was damaged by curling the bucket and hitting the ground [done before I got it!]
So, my first mod was to vacate all the flat fittings and go to the ‘zerk’ nipple type.

I then made a cover from scrap pipe and spot welded the cover over the lower part of the rod clevis to protect it from future injury. The original brass flat fittings, I gutted and soldered the ends closed and put them back in place with a little paint to cover them.
I lowered the bucket onto a reddish board and it did its job!

Getting to the battery is a little bit of work. I wired in a 2-prong plug to the battery, exiting near the boom actuator base. It can be used to either charge the battery, or attach a solar charger, just to keep the battery charged during down time.

Got other stuff in the works, but no hurry. Thanks for asking.

 

[dfkrug]

Other than the warranty repairs I did in the first year of ownership of my XN08, this is the first repair I did:

My bucket cylinder rod had a small ding in it, probably from shipping or handling. After 20h of use or so, the drip was more than I could live with. So I swapped out the cylinder in the field with one of my spares, and put the leaky one on the shelf for later.

A few years later, I took it apart and fixed it with a new gland-to-rod seal I bought on eBay, shipped from China. Less than $10 total, BTW.

Some surprising things about this cylinder: The gland unscrewed like most cylinders, but the piston was internally threaded instead of having a nut.

The piston had dual flat spots for gripping. I used a 24" adjustable wrench with a 3-foot cheater pipe, and it eventually surrendered. I had to put a bar through the cross-tube and drive the tractor on top of it. The maker had used thread-locker.

The maker also used a piston-to-rod seal, Glad I did not resort to heat to get that piston off.

Everything looks well-made with rub rings inside gland and on the piston.

I love the Chinese seals that have the metric sizes printed right on them. Easiest seal purchase I have ever had.

BTW, the maker of my mini quoted me $50 total for a full set of seals for all 4 cylinders, shipped via air. I forgot to buy those spares in advance with the XN08, and had no easy way to pay them, so I did not buy.

 

[JamesTheNextDoor]

One of the brackets connecting the boom and arm has bent. The pin shaft broke and flew off somewhere.

If you compare it with major mini excavators, you can see the difference. They have wedge-shaped reinforcement structures welded between the brackets.

I decided to grind down the elongated part and align the gap between the two brackets.

First, I welded a reinforcement structure to the bracket that had no deformation and then used a bearing puller to straighten the bent bracket.

After aligning, I reversed the bearing puller to prevent excessive shrinkage during welding.

After welding the wedge-shaped reinforcement structure, I also reinforced the outside of the bracket.

Honestly, I didn't expect this part to fail, but fortunately, the bent part straightened out well, and the repair was completed successfully.

I plan to reinforce the kingpost as well, as it is very poorly made and might break soon.

 

[dfkrug]

One of the brackets connecting the boom and arm has bent. The pin shaft broke and flew off somewhere.

Are your pins center-bored for grease, and retained by a nut? Or? I assume they are only 25mm, but I can not tell from the photos.

If you put your machine name in your profile, we can all see what you have.

 

[JamesTheNextDoor]

Are your pins center-bored for grease, and retained by a nut? Or? I assume they are only 25mm, but I can not tell from the photos.

Yes, it's a 25mm pin with a hole for grease fittings, and modified to be secured with a nut.

If you put your machine name in your profile, we can all see what you have.

Sure. I'll do that.

 

[dfkrug]

Here is a repair I have not done myself, but it will eventually be needed: replacing the bearings on the idler wheels. If your track tension is too tight, this will hasten the wear on these bearings.

I found this on a public facebook group yesterday, and I am including the photo posted by that user (I will credit him if he wants).

It looks like 2 off-the-shelf ball bearings with a shaft retained by roll pins. An easy fix, even if the shaft gets damaged. If your idler wheels wobble, or the tracks come off too easily, you may want to explore this repair.

 

[dfkrug]

I was doing the spring upgrade to a Diggit EM15 the other day, and I noticed this problem with the engine speed control lever.

This is the same unit seen on virtually all of the 1-ton-ish Chinese minis, with the push button in the middle.

I see that water easily gets in, and pools inside, rusting the spring. Both the button and outer handle thread on separately. What's the repair? Take it apart, grease the threaded parts, and put a big dollop of grease in the recess where the spring goes. One could even drill a hole in the outer part of the handle so water drains out.

Then, keep your machine out of the rain, and protect the throttle control if washing it.

So far, my 7yo XN08 has had fewer repairs than modifications.

 

[MattB4]

I recently picked up a hydraulic test kit thinking of checking and adjusting my TT-17's relief valve. The kit comes with metric adapters but they are not DIN style that the excavator hoses are. What adapter is it and does anyone have a source for a 14M test female(or 3/8 or other combination) by 14M Din male? I see several videos where people hook up their gauges to boom hoses but none of them tell where they get the fittings to do so. Test fittings are flat faced with a O-ring above the threaded portion whereas DIN are a insert seal.

I searched repeatedly online and never seemed to find such a fitting. Thanks if anyone has a answer.

 

[dfkrug]

What adapter is it and does anyone have a source for a 14M test female(or 3/8 or other combination) by 14M Din male? I see several videos where people hook up their gauges to boom hoses but none of them tell where they get the fittings to do so.

I suppose I am guilty. Here is why:

When I got my first machine and posted that video back in 2018 or -19, I just welded up a NPT-to-DIN 2353L port to connect my gauge to the hose connector on the dipper.

Since then, I encountered different size hoses for the AUX, either M12 or M14 (-6 or -8).

DHH does not have an adapter for NPT to DIN 2353L port. Most gauges are 1/8 or 1/4 NPT. In your kit, maybe not.

So, I suggest you go with a DHH 9624 JICF to DIN 2353 and adapt the JIC to your gauge:

9624-06-L08-14 | 3/8" JIC Female x M14x1.5 Metric Male (fits 8 mm tube)

Check out the deal on 9624-06-L08-14 | 3/8" JIC Female x M14x1.5 Metric Male (fits 8 mm tube) at DiscountHydraulicHose.com

www.discounthydraulichose.com

These adapters are very expensive, so welding one up for occasional use should be considered.

Attached pix show what I got for the AUX connection on the dipper on my minis.