Hydraulic Oil Filter... Why?

[dlundblad]

*wrong thread. Oops.

 

[burbguy82]

I would think a filter belongs in the return line. Dust/debris/etc. are created in the system, and this catches it before the reservoir, where system pressure is lowest, but it still positive pressure. A filter in the suction line would inhibit the pump drawing fluid in. A filter on the output side of the pump would have to deal with very high pressure.

So, return line.

I was not suggesting to the OP that one should be added to the suction. I was asking if there was one in the tank. Mine has 4 separate filters for the hydraulic system....one of which they call the suction filter. It is in the bottom of the tank, under 15 gallons of fluid.

https://www.messicks.com/parts/kubota/68773-62210

It is a very large filter..........made of stainless steel, really high quality.

Mine also has a return filter.

Point being, they do exist and are installed on machines.

 

[4wd]

2weeks? Oh the horror! Here its doesn't rain for months/ year. lol

Hopefully you know dust is dust wise-Guy …

 

[4wd]

@BigJohn
Former Hydraulics engineer and hydraulic system designer...

Several good answers here, pumps (especially gear pumps) do make some contamination. There is some left over from machining, that is also correct. There are some wear metals in the "clean" oil added to the system. The hoses are a pretty big contributor both when they are first put on dirty, and as they slowly erode due to fluid flow. But...THE MOST MAJOR source of contamination was right there in your statement...

"controls to the cylinders"

Those cylinders are exposed to dust, buried in water, shoved into the dirt, etc. The seals on those cylinders are not perfect. Cylinders are the #1 contributor to system contamination. Clearances in low leak valves and axial piston pumps range in the 5-30 micron range...these are precision machined components. ANY contamination can cause wear and damage.

I believe dust is actually introduced in component testing to see what’s tolerable - and it does not take much to create premature failure …

 

[bigjohn]

There are two screen filters in the tank... They are better than expected. But I want to add a screw in filter and will add it in the next 30 days.

 

[Chris142]

I baited all of you into a conversation, where I wanted your opinion without bias... Now here is my situation, and if I would have started with this... bias would have run wild.

I just purchased a mini-excavator..... yep, of the Chinese variety. Yep, at the $5,000 amount or so.

It did not come with a hydraulic filter.

Since I started this thread, I have learned that I can probably add a full filter setup for about $100-$120.

What you have convinced me of is.... I absolutely need to add the filter.

Thank you.


.........

It should have a sock filter inside the tank.

 

[DriveHard]

It should have a sock filter inside the tank.

intake strainer...AKA "boulder catcher"

 

[cmarshall78]

The transmission and hydraulic sump are shared on any farm tractor built in the last 50 years.

 

[DriveHard]

The transmission and hydraulic sump are shared on any farm tractor built in the last 50 years.

The machine in question is a mini excavator, not a tractor. I'm guessing there are no wet clutches in this machine, and no need for tractor fluid...it most likely is running hydraulic fluid.

 

[cmarshall78]

The machine in question is a mini excavator, not a tractor. I'm guessing there are no wet clutches in this machine, and no need for tractor fluid...it most likely is running hydraulic fluid.

This 1st line says pick your farm equipment. I wouldn't call a mini excavator farm equipment.

 

[cptbarkey]

I wouldn't call a mini excavator farm equipment.

Welcome to the world where mini excavators are considered farm equipment.

 

[CT Rob]

A filter is MUCH cheaper and easier than replacing a very expensive hydraulic pump .