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

[mini-mayhem]

I recently bought the backhoe that came attached to a tractor, it has been slow to move and intermittent on if it will move at times. the previous owner said he had changed the oil and filter but not checked it after ( alarm bells should have been ringing...)

with a warm spell in the weather ( +6 degress C) i decided I would take a look at it.
The right rear stabiliser wouldn't push out.
So I thought perhaps there was air trapped in the lines or cylinder so i took a spanner to the hose fitting and lossened it to let the air out - however the oil looked like ice-cream!

The milky oil did bleed away to leave new oil, however ther was still lots of air bubbles, so I opened it up to let the cyclinder bubbles out

Now I was short of oil, so I thought I would top off the cylinder and the tank. off came the tank cap, and whats that in the mesh?

to the workshop and scrape it out.

a metal fragment about the size of a jacket zip. well, thats not great but at least it wasn't floating around in the system. Actually, what is floating around in the system? A quick dip with a magent on a stick and...

oh dear, wipe it off and have another dip

and n dips later

This looks to have some balls of metal in it, not just the swarf, but multiple recognisable balls. but from where?

That sets up our story. The next job is to get all 7 cylinders off the backhoe and into the local hydraulics shop for strip, clean and inspection for further damage.

Any tips on cylinder removal, pump strip down or control valve servicing?

 

[Jsjac]

Hopefully this backhoe used a pump that runs off the PTO and not the tractor hydraulic system?

 

[mini-mayhem]

Hopefully this backhoe used a pump that runs off the PTO and not the tractor hydraulic system?

Correct, its PTO driven so all the contamination is isolated to the backhoe. A saving grace.

 

[Jsjac]

Almost looks like mig welding wire.in one picture.
Was that in the tank past the fill screen?
That sounds like it will be a good size job getting all the cylinders to the shop.

I have done repairs to lots of hydraulic systems. That looks like some odd contamination. Usually you see fine shavings. Big pieces from a small gear pump like that is using is very odd.

 

[GreensvilleJay]

ok.. milky white is a mix of oil and WATER. Water can get in through the vent cap on the hydraulic tank,either as rain drops or humidity.
Before you remove all the cylinder, drain ,flush as much oil as possible x 2 , refill with economical universal tractor oil ( I use Walmart for decade + ). run tractor, engage PTO and see how things operate.
The filter DID it's job ! so you may be alright. if you do need to remove the cylinders, take pictures, make notes, tag them and 'rag' the ends of the hoses (keep 'stuff' out,like wasps and spider.s...)

 

[fried1765]

ok.. milky white is a mix of oil and WATER. Water can get in through the vent cap on the hydraulic tank,either as rain drops or humidity.
Before you remove all the cylinder, drain ,flush as much oil as possible x 2 , refill with economical universal tractor oil ( I use Walmart for decade + ). run tractor, engage PTO and see how things operate.
The filter DID it's job ! so you may be alright. if you do need to remove the cylinders, take pictures, make notes, tag them and 'rag' the ends of the hoses (keep 'stuff' out,like wasps and spider.s...)

How can everything possibly be "allright" with HUNKS of metal being found?

 

[Jsjac]

What was on the bottom of the tank. Was there metal after the filter?
If the tank bottom is clean ,I would say try it.
If there is metal on the bottom of the tank it needs to be cleaned out.
At this point if the tank is clean or cleaned out I would try it .what do you have to loose at this point.
The replacement pump would be the easiest part of the process. Dealing with the cylinders and valves would take the most time.

Not sure how available parts are in Latvia. Good luck with the project

 

[mini-mayhem]

Almost looks like mig welding wire.in one picture.
Was that in the tank past the fill screen?
That sounds like it will be a good size job getting all the cylinders to the shop.

I have done repairs to lots of hydraulic systems. That looks like some odd contamination. Usually you see fine shavings. Big pieces from a small gear pump like that is using is very odd.

Yes, all those metal pieces were in the tank past the screen.

Hopefully I'll soon be able to tell you where they are from.
It feels like a big job, as I am 3 cylinders in amd 4 more to go ( the awkward ones) then i will have them all removed and ready for the shop

 

[mini-mayhem]

ok.. milky white is a mix of oil and WATER. Water can get in through the vent cap on the hydraulic tank,either as rain drops or humidity.
Before you remove all the cylinder, drain ,flush as much oil as possible x 2 , refill with economical universal tractor oil ( I use Walmart for decade + ). run tractor, engage PTO and see how things operate.
The filter DID it's job ! so you may be alright. if you do need to remove the cylinders, take pictures, make notes, tag them and 'rag' the ends of the hoses (keep 'stuff' out,like wasps and spider.s...)

Thanks Jay,
I will be sure to rag the hoses. I have been photographing and cable tie labeling each hose.

 

[mini-mayhem]

What was on the bottom of the tank. Was there metal after the filter?
If the tank bottom is clean ,I would say try it.
If there is metal on the bottom of the tank it needs to be cleaned out.
At this point if the tank is clean or cleaned out I would try it .what do you have to loose at this point.
The replacement pump would be the easiest part of the process. Dealing with the cylinders and valves would take the most time.

Not sure how available parts are in Latvia. Good luck with the project

Yes, the metal on the magnet was from the bottom of the hydraulic tank.

The backhoe wasn't working right, it was vey slow to make an movement. I don't know the history of it and I suspect that there has been some damage by a previous operator. If I rebuild it all now it should be good and reliable for the future.

I am about to find out about parts availability . Cylinder servicing is locally available , valves and pump I dont know about.

 

[mini-mayhem]

This pin took longer than the other two cylinders to remove, it looks like its mushroomed on the end and has some wear in the centre, I'll tidy it up before refitting. Boom cylinder removed!

Bucket cylinder removed, that went quite well.

Backhoe ready for disassembly with over head gantry washing line in place.

 

[Trimley]

Sounds like Mr. Fixit> Fixed it one last time, before he was looking at a lot of time and money to fix it right. Hopefully you got the BH on the cheap. By time you're done, it will almost have involved a complete rebuild.

Atleast all said and done, you'll know what you got.

 

[fried1765]

View attachment 118512 This pin took longer than the other two cylinders to remove, it looks like its mushroomed on the end and has some wear in the centre, I'll tidy it up before refitting. Boom cylinder removed!
View attachment 118515 Bucket cylinder removed, that went quite well. View attachment 118517 Backhoe ready for disassembly with over head gantry washing line in place.

Interesting project.
Hope it works out well for you!

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

 

[colt63]

There is probably an oil drain on the bottom of the oil tank. Drain out the old and I would flush with cheap oil or diesel fuel. Maybe both.
Perhaps I will check the oil in my back hoe. All I ever do is check the oil level. Two years ago, I had two of my cylinders re-sealed because they started to leak oil. As I remember, It was about $100 each. I could have bought a "set of seals", but they were about $80 each; and if I broke one in the process...

 

[PoTreeBoy]

Does all the return oil go through that mesh? It obviously didn't catch some sizeable pieces.

Could you install a filter on the pump suction line? You need to catch that junk before the pump. Probably need to clean the valve too.

 

[mini-mayhem]

Sounds like Mr. Fixit> Fixed it one last time, before he was looking at a lot of time and money to fix it right. Hopefully you got the BH on the cheap. By time you're done, it will almost have involved a complete rebuild.

Atleast all said and done, you'll know what you got.

All in I could consider the backhoe to be about €1,000 worth.

Yes, it has had some abuse from previous owners. If I rebuild it I'll know what i ahve is good and get many years of good service from it.

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

cocaine, it just falls from the sky

There is probably an oil drain on the bottom of the oil tank. ... Two years ago, I had two of my cylinders re-sealed because they started to leak oil. As I remember, It was about $100 each. I could have bought a "set of seals", but they were about $80 each; and if I broke one in the process...

No oil drain on the bottom of the tank, there is only the connection for the suction hose to the pump, it might be an idea for me to install a magnetic sump stud there.
I also think the price of the shop doing it will be cheaper than me breaking something

Does all the return oil go through that mesh? It obviously didn't catch some sizeable pieces.

Could you install a filter on the pump suction line? You need to catch that junk before the pump. Probably need to clean the valve too.

I'm not sure how that mesh works, as it sits in the filler neck.
There is an oil filter on return line from the valve block, but on the suction line makes alot more sense

 

[GreensvilleJay]

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.

 

[North Texas Rich]

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.

 

[North Texas Rich]

I would have new lines made since you already have them off. It will save you the trouble of cleaning them or having them burst and make a mess while on the job.

 

[North Texas Rich]

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