A thought came to mind of how many people/companies run hydraulic oil filter carts while doing there service.Also draining the tank while filtering into clean drums and cleaning the bottom of tank,changing hyd oil.One would be amazed at what is in there.

Many,

You are right. The bottom of a hydraulic tank after the pump has been in service for a year is/can be nasty. Cleaning the tank and doing a filter change - both - is a good way to save $$$

An unusual ammount of care must be taken with every step of the procedure. Lint free rags, clean transfer hoses both inside and out, clean drums..... etc.

Most contamination is PUT INTO a pumps hydraulic system by poor procedure. The internal wear is a factor, no doubt, but the crud that is added to the system while topping off is extreme. That is one reason I don't like the [E-Z] program of taking aggitator oil to oil down a hopper; when the top-off oil is added back to the tank the crud often times comes with it. ;~)

well said bob, fist dump your water box EVERY DAY second replace your filters every three months dump the oil clean the tanks once a year, your pumps, pulsars and so on will thank you.

MR a valid point.I can't help but wonder how many operators don't pay attention to whats going on there.There's some oil in the water box,oh well now concrete won't stick.Those rod packings are very an important part of the life of the system.Another thought is as a hyd pump wears the metal must go somewhere,or guts missing from check valves and such.How many have seen the tank filter blown apart ?.Now what happens to the filtering on return to tank oil.

We have a custom built cart for this.  I'm not sure of the specifics but you suck the oil out of the tank and it gets filtered in the process. There's a guage on the tank etc.... then when you're done servicing you pump it back into the tank as it's filtered again, I'll have to take a picture of it.

There are a bunch of different cart manufacturer's out there.I got mine from Granger.It has 2 filters on it.A 10 micron and a 3 micron.Works very well.I filter every 3-4 months for a min of 8 hours.The biggest thing that contaminates the oil is the that the cap and filler area are not clean before cap is removed and oil is  added. 

Filter carting oil is OK but don't think that that is a end all of oil maintenance .The manufacturer of the machine makes a big difference in the case of a Putz the have filters before the pumps so filtering without a regular filter change is not the answer because the cart only cleans whats in the tank and thats it .

Although not that familar with Putz I would have to ask this.What happens when filter becomes abstructed?.Does it not bo into bypass allowing contaminates to flow around filter?.

Yupper