Cleaning up oil in your system

[JRP]

After a heavy rain period I noticed a split in the shifter boot on my M6800. Decided to check the tranny/hydraulic fluid and it was like pea green soup, emulsified water in oil. Changed the boot, filters, and oil. I used a Donaldson spin on hydraulic filter from ebay, connected to a remote port to "kidney filter" the system. The filter outlet hose is inserted into the oil fill hole. The Donaldson housing has a built in 25 psi bypass valve to protect if the filter becomes plugged. The model of housing I purchased, however, is not drilled and tapped for a pressure gauge. Other model numbers come pre drilled and tapped for a gauge. I drilled and tapped the housing inlet side 1/8" pipe thread and installed a 100 psi gauge, glad I did because a fast idle result in 12 psi inlet pressure and I don't want to get above 20 psi. I installed the filter and ran the tractor behind the shop for a half hour to clean up any particles in the oil. If the filter inlet could remain below 20 psi At PTO speed I could rig up a return hose such that it could filer while I use the tractor. I hope the idea helps you folks wanting to clean up your system.

 

[RalphVa]

Did one filter do it? If you had very much water, you might do with a settlement chamber after the filter or one of those filters with a water decanter on the bottom of it.

Ralph

 

[oosik]

I worked for a company that used very large plastic injection molding machines. Everything ran on hydraulics. These machines averaged around 450 to 600 gallons of hydraulic fluid per machine. Where I worked we had 28 of these machines.

The maintenance staff had two hydraulic "filter and purification" machines. About the size of an average steel office desk. They had each machine on a schedule and would roll these purifiers around the building to do their clean-up on the machines.

It appeared that these purification machines ran about two shifts(16 hours) on each machine. They would cycle the hydraulic oil thru many different filtering process's and return it to the large holding tank on the hydraulic press.

Then at some unpublished, secretive schedule - each machine would be out of service for a day or so. The hydraulic fluid would be totally pumped out - a large access port would be opened - the gallons of "guck" would be shoveled out - somebody had to go inside this storage tank and clean it darn near spotless with sponges, squeegees, suction pumps and finally a boat load of shop rags.

 

[JRP]

After changing the oil I Mowed for a day, then took a 1 gallon sample. There was no free water in the sample. The kidney filter did not plug up, inlet pressure dropped as the oil heated up, as it should.

It is a simple way to filter the oil better than the factory suction filters.

 

[Texasmark]

Thank you for sharing that with us.

 

[SilentJ]

The 100 psi gauge doesn’t tell you much until you know what the internal bypass in the filter is set for

Most (not all, have to get the Donaldson part number to determine it) filters have a spring loaded check that opens when it takes a certain pressure to push fluid through the filter. Called a bypass. Intended so that oil doesn’t deadhead and blow the filter off when the element becomes plugged with dirt, and also to let oil circulate during cold winter starts when the oil is thick.

Most “return” filters typically have a 25 PSI bypass. When flowing you will see the gauge “peg” above 25 psi when the filter is clogged with enough contamination to make it harder for the oil to be pushed through it

Water is another matter. A typical filter doesn’t remove water all that effectively. Special filters have desiccant properties to remove water, or you can drain the oil after sitting for a while ... the water should eventually settle to the bottom but much of it can get emulsified in the oil and have trouble settling 100% out.

 

[SilentJ]

I worked for a company that used very large plastic injection molding machines. Everything ran on hydraulics. These machines averaged around 450 to 600 gallons of hydraulic fluid per machine. Where I worked we had 28 of these machines.

The maintenance staff had two hydraulic "filter and purification" machines. About the size of an average steel office desk. They had each machine on a schedule and would roll these purifiers around the building to do their clean-up on the machines.

It appeared that these purification machines ran about two shifts(16 hours) on each machine. They would cycle the hydraulic oil thru many different filtering process's and return it to the large holding tank on the hydraulic press.

Then at some unpublished, secretive schedule - each machine would be out of service for a day or so. The hydraulic fluid would be totally pumped out - a large access port would be opened - the gallons of "guck" would be shoveled out - somebody had to go inside this storage tank and clean it darn near spotless with sponges, squeegees, suction pumps and finally a boat load of shop rags.

Shouldn’t have been based on a secretive schedule, but by a combination of online contamination monitoring (laser particle counter or something like that), or by simply installing pressure drop gauges to see the restriction as fluid passed through the filters to determine the elements were clogging and needing replacement.