Clogging of Filters used in Hydraulic System - Due to Cellulosic Material

[Ethan Ng]

Hi,

A particular filter that is in use for the Hydraulic System of an aircraft that i maintain, keeps on clogging. When we cut open the filter, we find that it is heavily clogged with a dark greyish substance. When we send the dark greyish substance to the Laboratory for examination, the laboratory told us that the substance is a cellulosic material. I'm puzzled because i'm not aware of such material being used in the Hydraulic System. Does anyone have a similar experience?

One possible suspect is the filter itself, but when I tried to look through the filter OEM's website, but there is no material of the construct of the filter there.

Thanks in advance, and regards

Ethan

 

[3DDave]

Maybe someone left a rag or paper towels or tissue in the system; perhaps the tank.

The crack team of assemblers I worked with did that with the cooling system on a diesel, put a rag in a line to keep the coolant from dribbling or some such while servicing. I guess the rag got pushed back where it wasn't hanging out anymore. A 2 stroke supercharged diesel actually depends on cooling and rag as found throughout the heads.

Best of luck finding it. I'd start with any reservoir.

 

[hydtools]

Maybe paper hand towel.

Ted

 

[TugboatEng]

What is the hydraulic fluid? Is it possible there is some degredation or contamination of the fluid? Esters and cellulose aren't too different in terms of atomic makeup.

 

[Compositepro]

I think the lab just told you that you have a paper filter.