KMS 180 backhoe / backactor Metal in oil and how to fix it.

[steveh]

The large piece of steel inside the tank probably didnt come from inside the system.

This is what occurred to me

 

[mini-mayhem]

The mesh in the neck is supposed to keep 'stuff' from getting INTO the tank.Unless it's fastened somehow, you have no idea when it was installed. Since there were 'items' bigger than the holes in that screen on the bottom of the tank, it wasn't doing it's job.
I'd have thought there would be a 'drain port' on the tank, maybe on the side ? If not, I'd add one. Remove the tank,clean tank, drill hole, weld 'pipe flange' piece on. If NO chance it can be damaged, put on bottom, otherwise on a side wall. You can buy pipe plugs with magnets on them or make your own.
If possible find parts drawings of the unit (maybe the WSM ?) to see how it was built. Unlikely to need to modify the unit though.
Curious just how old is the beastie ? Two of my tractors had 1/4 - 1/2" of 'gunk' in their hydraulic sumps yet hydraulics worked great.

Yes adding the drain is now on my list to add. I have the WSM, it's helpful but not comprehensive.

 

[GreensvilleJay]

If possible add the drain where it won't dribble all over the tractor when you pull the plug....
unlike the engine on my walkbehind rototiller.......sigh.....

 

[mini-mayhem]

After the cylinders are out for repair I would replace the pump. Those little shavings are from it more than likely. Tring to rebuild it may not be the best the since the heat treated surfaces have been damaged and the soft steel core will wear much quicker and contaminate the system and ruin the new seals in the cylinders.
The pressure relief should also be removed, cleaned and set to correct pressure. Controls should be cleaned and new seals done.

Rich, that's some sound advice. I'm sure that the pump is a likely culprit for the contamination.
My plan is to clean th enewer lines and replace the old cracking lines at this time.

 

[mini-mayhem]

On the age thing, this backhoe was for models produced between 1981 and 1990. so we have an age range of 42 to 33 years in service!

All cylinders are now removed, along with the pump.
Slew cyclinders were straight forward, undo the 4 bolts and remove the caps, then lift and wiggle the ram out the back.

The next challenge was the leg rams, the obvious issue is that I can't simply extend them down as there isnt enough clearance, Titling the whole frame worked a treat and allowed the legs to slide out... it wasn't that easy though! It tooks lots of hammering to persuade the left leg to come out, the right leg needed even more work, including defrosting, but I got there and now have all the cylinders out and ready for the shop after christmas.

And the sweet relief of getting it out

The leg was full of liquid, no doubt a mix of oil and water which had frozen and prevented the movement, not help by the bulging of the leg post, no longer a flat slight, but bulging out and causing hard contact. this will be rectified before refitting.


7 cylinders out
Pump removed to be stripped on the bench

Next steps
Valve removal to go to the hydraulic shop.
Hoses - swap the oldest ones for new, change the pump sution hose for a hydraulic hose.
Tank, remove, clean, add boss for magnetic sump stud, add oil level gauge.

 

[fried1765]

On the age thing, this backhoe was for models produced between 1981 and 1990. so we have an age range of 42 to 33 years in service!

All cylinders are now removed, along with the pump.
Slew cyclinders were straight forward, undo the 4 bolts and remove the caps, then lift and wiggle the ram out the back.
View attachment 118622

The next challenge was the leg rams, the obvious issue is that I can't simply extend them down as there isnt enough clearance, Titling the whole frame worked a treat and allowed the legs to slide out... it wasn't that easy though! It tooks lots of hammering to persuade the left leg to come out, the right leg needed even more work, including defrosting, but I got there and now have all the cylinders out and ready for the shop after christmas.
View attachment 118623
View attachment 118624

And the sweet relief of getting it out View attachment 118625

The leg was full of liquid, no doubt a mix of oil and water which had frozen and prevented the movement, not help by the bulging of the leg post, no longer a flat slight, but bulging out and causing hard contact. this will be rectified before refitting.


7 cylinders out
Pump removed to be stripped on the bench

Next steps
Valve removal to go to the hydraulic shop.
Hoses - swap the oldest ones for new, change the pump sution hose for a hydraulic hose.
Tank, remove, clean, add boss for magnetic sump stud, add oil level gauge.

Enjoying your progress reports!

 

[GreensvilleJay]

looks like he's all 'fired up' and making GREAT leaps and bounds !!
he can keep that white stuff though.........
..until the 29th, then I'd like a HUGE donation of white..

 

[DustyRusty]

Interesting project.
Hope it works out well for you!

From Florida: What is that white stuff on the ground?

Ivory Snow Flakes

 

[DustyRusty]

With the amount of miscellaneous iron rubbish in the tank, might it be that one of his neighbors sabotaged the backhoe for some unknown reason? I have noticed that on road construction jobs most, if not all the larger machines have locking hardware on the tanks that contain oil. Smaller equipment is hung by steel cables in the air. You never know what type of mischief a disgruntled person is capable of.

 

[fried1765]

Ivory Snow Flakes

My mother always bought "Ivory Snow Flakes".
Do they still sell that stuff?

 

[mini-mayhem]

The worshop manual I purchased is now available for free from kubotabooks.com

https://www.kubotabooks.com/AutoIndex/index.php?dir=Backhoes/&file=KMB%2C%20KMK%2C%20KMS180%20%26%20KM190%20Workshop%20Servi...Manual.pdf

 

[mini-mayhem]

Another day of lesuirely progress on the back actor.

First job was to get it standing, so I would have access to the control valves and hoses.

With the corrdct orientation acheived, I set about labelling the hoses on the control block. and then removing the valve block.

Valve block free.

That marked the point where all the big hydraulic parts are removed.

The leg cylinders were looking very crusty, with plenty of rust eating away at the cylinder body.
I cleaned up the worst of it with the angle grinder wire brush. I wiped all the cyclinders downa nd loaded them into the 'truck' to drop off at the hydraulic shop.

With the hydraulic shop kept busy, I had some time to look at the pump.

I took it into the "clean room" to begin teardown

With an unreadable ID tag

I cracked on with dismantling

out came the bolts on the end of the pump, hide faced hammer to get the end plate off and there were the gears

All looked good there, the back of the cover plate also looked good apart from a few needle rollers that were misplaced in the removal process.

Behind the inner plate were the gears, these also looked good, and when turning the PTO input by hand there was oil being displaced, all good there.

Then I split the pump from the gearbox, so I could remove the gear for inspection, the gearbox end didnt look so impressively clean.

 

[GreensvilleJay]

wow, you've really got a 'project' !!! Nice to see the pump clean inside..
you can use some grease to hold the needle bearings where they belong when reassembling. Far fewer than the DOUBLE rows that were in an old Willys transfer case I rebuilt !
If the case doesn't slide on nice and fit flush by hand, pull it off and check for a single needle bearing that's fallen down, laying flat on the bottom...BTDT... if it happens use MORE grease !

 

[mini-mayhem]

With the pump detacthed from the gearbox, I was able to push out the pump gear and take a closer look.

The pump teeth are in great condition, no chips, or meshing clashes. The bearing surface is little shiney.
I was feeling quite pleased that the pump looked to have a clean bill of health. A quick clean and I could get it back together!

So clean I did.

Oh boy!

What have we here? Or rather what haven't we here!

From the end I have drawn in yellow the worn tooth profile and in blue the approximate unworn tooth profile.

Well, that would certainly reduce the effectiveness of the pump! The gear doesn't look to be removeable, it is a single piece shaft.
The wear seems to be caused from PTO input which was bouncing around in the housing when I moved it by hand.
I'll try to get a little video for you of the wobbling.

I don't know if the shaft can be repaired, but I suspect even if it can it won't be economical. I'll have a look for a PTO pump...

 

[mini-mayhem]

http://imgur.com/a/f7oPIzI

Hopefully you can see the video of the wobble the PTO input has.

 

[fried1765]

http://imgur.com/a/f7oPIzI

Hopefully you can see the video of the wobble the PTO input has.

THAT wobble....is certainly not good!

 

[North Texas Rich]

Needs a new pump

 

[North Texas Rich]

Dont forget to check the other side that gooched up drive shaft connects to. You might need one of those too.

 

[mini-mayhem]

New pump ordered.

https://hydraulikmeister24.de/de/69-Zapfwellengetriebe-BG2-138-mit-Schiebemuffe-20ccm-Pumpe-BG2.html

I should be well set up now to get on cleaning the tank and hydraulic lines.

 

[GreensvilleJay]

aw... you 'cheated'.. I was hoping to see a full length video of you TIG welding new teeth onto the pump shaft, filling them to SAE dimensions, balancing the shaft and then reinstalling the rebuilt pump !

have to admit that new pump does look a LOT better than the original, that must have a zillion revolutions on it.