Have a Hydraulic Problem but Lacking Motivation in Solving it...

[Henro]

I parked my old KX41-2V mini-ex a couple months ago, and all was well when I shut it down.

A few weeks later I decided to use it for something, and the hydraulics did not works properly, but some functions did work, while others did not.

Rather quickly, all stopped working. The excavator has three hydraulic pumps. It is under roof so it can wait awhile for my interest to perk up. At this rate, it will be next spring, since I don't like the cold, and have no reason to get it working again quickly.

Glad I did not sell my 3PH backhoe, by the way! LOL. We all know how useless they are...LOL It was my backup and did what I needed done.

My lack of progress is simply due to not taking the time to fully examine and understand the hydraulic schematic. I will do that over the next months.

BUT the unit has three hydraulic pumps, which serve different functions. Or may work in tandem sometimes.

I keep thinking that they all should not fail at the same time. So this leads me to thinking maybe the first coupling to the pumps failed somehow, and that may be the likely issue.

The engine starts fine, immediately, any time I try it, even in freezing temps to date.

I did check hydraulic fluid level and it was a little low, but not that bad. I added fluid and probably slightly over filled it, but not a lot.

One other thing...as things started to stop working, some functions quit before others. Now nothing works.

When I bought it "Next Service XXXX hours" was painted on it. I have not hit that number of hours yet, so I did not change any fluids of filters.

Could a collapsed hydraulic filter cause this symptom?

Anyone like to offer a WAG or two?

 

[TheOldHokie]

I parked my old KX41-2V mini-ex a couple months ago, and all was well when I shut it down.

A few weeks later I decided to use it for something, and the hydraulics did not works properly, but some functions did work, while others did not.

Rather quickly, all stopped working. The excavator has three hydraulic pumps. It is under roof so it can wait awhile for my interest to perk up. At this rate, it will be next spring, since I don't like the cold, and have no reason to get it working again quickly.

Glad I did not sell my 3PH backhoe, by the way! LOL. We all know how useless they are...LOL It was my backup and did what I needed done.

My lack of progress is simply due to not taking the time to fully examine and understand the hydraulic schematic. I will do that over the next months.

BUT the unit has three hydraulic pumps, which serve different functions. Or may work in tandem sometimes.

I keep thinking that they all should not fail at the same time. So this leads me to thinking maybe the first coupling to the pumps failed somehow, and that may be the likely issue.

The engine starts fine, immediately, any time I try it, even in freezing temps to date.

I did check hydraulic fluid level and it was a little low, but not that bad. I added fluid and probably slightly over filled it, but not a lot.

One other thing...as things started to stop working, some functions quit before others. Now nothing works.

When I bought it "Next Service XXXX hours" was painted on it. I have not hit that number of hours yet, so I did not change any fluids of filters.

Could a collapsed hydraulic filter cause this symptom?

Anyone like to offer a WAG or two?

My WAG is you will quickly find the problem after a little study of the hydraulic schematics.

Dan

 

[Russell King]

If the filter is on the pump inlet, and clogged and collapsed it would stop the hydraulics from working just as if a pump mechanically failed.

 

[North Idaho Wolfman]

Correction alert: You have 4 pumps.

I would say off the top of my head it sounds like you have a suction issue.

 

[Trimley]

My WAG, you'll not be bothered with it now or in the near future, but you may as well make an appointment at the dealer to have it looked at. You "might" get lucky if they have an opening now, for next Spring

 

[Henro]

Correction alert: You have 4 pumps.

I would say off the top of my head it sounds like you have a suction issue.

As usual, the Wolfman speaks the truth!

My original hydraulic diagram did show something, but it was not apparent to me it was a pump because the copy was poor and some lines were missing.

A member here sent me a copy of the Operator's manual, and it has a better copy of the hydraulic schematic. MUCH better.

So the diagram shows three pumps marked P1, P2 & P3 to the left of the engine (ENG) symbol, and a forth circle labled Pp to the right of the ENG symbol. I missed the forth pump. So my memory was accurate, but vision was poor! LOL

BUT this leads to a question. Does showing pumps on both sides of the ENG symbol indicate that the engine may have shafts coming out of each end of the crank shaft to drive hydraulic pumps? With one pump on one side, and three on the other?

I can post a picture of the section of the drawing showing this later if it would be helpful. Can't easily do it from this computer.

I will look at the WSM and see if it answers this question, or if the better quality operator's manual might. But I am sure someone with experience reading hydraulic diagrams will likely know the answer without blinking.

 

[Henro]

My WAG, you'll not be bothered with it now or in the near future, but you may as well make an appointment at the dealer to have it looked at. You "might" get lucky if they have an opening now, for next Spring

That's not a WAG! That is certainly accurate insight!

Actually, being a quite old mini ex, the only dealer in the future will likely be the scrap dealer.

BUT I hope it doesn't reach that point, and that I get it functioning again and pass it on to someone else for cheap, if in the future I would reach the point of wanting something newer.

 

[amschind]

My tractor's hydraulics completely failed due to 1) fluid which was much uglier than the filters would've suggested and 2 a bunch of debris from a brake job clogging those filters; completely fixed after fluid and filter change My rule is that every fluid which can reasonably be replaced gets replaced when I get a "new to me" machine of any description, and that has proven particularly useful now that I'm buying stuff with hydraulics. Your "Everything quit working all at once" sounds a lot like my issue, so there is hope that narsty fluid and/or clogged filters are the (cheap to fix) culprit.

 

[Henro]

Funny, but at some point in my career in heavy industry involved with solving issues with relatively complex control systems, I realized that it is possible to solve control issues without totally understanding the system one is troubleshooting. By simply applying common sense!

This was a eureka moment for me, because I had always concentrated in understanding systems I was involved with in great detail. BUT I ended up in a position that did not make studying and understanding the systems quickly possible.

Starting to think that same approach may work in my current situation. Focusing on the supply (suction) side may be something to address before thinking too much...

 

[amschind]

Funny, but at some point in my career in heavy industry involved with solving issues with relatively complex control systems, I realized that it is possible to solve control issues without totally understanding the system one is troubleshooting. By simply applying common sense!

This was a eureka moment for me, because I had always concentrated in understanding systems I was involved with in great detail. BUT I ended up in a position that did not make studying and understanding the systems quickly possible.

Starting to think that same approach may work in my current situation. Focusing on the supply (suction) side may be something to address before thinking too much...

The bonus for you is that swapping out the fluid and filters should get done regardless of an acute problem.....an ounce of prevention is worth a pound of cure.

 

[North Idaho Wolfman]

The Pp pump is run off of the fuel cam where P1,P2,P3 is run off the Crank.