Hyd Suction filters

[J_J]

I would just like to point a fact that some people are not aware of, mostly for other tractors owners.

The Power-Trac hyd filter system uses a 10 micron suction filter on the VSP pump. This is the only filter on the system. Some of the hyd tanks are 20 GAL. Some of use have installed inline high pressure hyd filters in the PTO system.

The way my system and others work, is the suction filter is the input to the charge pump, which pumps abut 10 % of the VSP pump, somewhere around 5 GPM, and is running all the time. It is also used to charge and flush the pump to help keep it cool. This is the only filter in the system, and the other two hyd pumps pump out of the hyd tank which has only been filtered by the one filter. The VSP pump is used in a closed loop system, and if the wheel motors have a case drain, that fluid goes back to tank through a radiator system.

The point to make here is that the systems on our Power-Tracs, seem to work quite well, as I haven't heard of any failures attributed to contaminated hyd fluid. By the way, the Power-Tracs use 10W-30 or 40 motor oil for the hyd fluid. Some use synthetic motor oil. One of the reasons for the use of motor oils, is that one can find motor just about anywhere, and we usually have some around the house/garage.

Some of us have cut the filters apart, and found some stuff in them but nothing significant. Maybe bits and pieces of hose material. A gage on the oil filter is recommend to catch a clogged filter if it should occur.



I think we all understand that if a suction filter clogged up, that it could destroy a pump, so we change it out about every 100 hrs. Cost about $15.

Just some data from the Power-Trac people that might help others dealing with hyd.

 

[MossRoad]

I would just like to point a fact that some people are not aware of, mostly for other tractors owners.

The Power-Trac hyd filter system uses a 10 micron suction filter on the VSP pump. This is the only filter on the system. Some of the hyd tanks are 20 GAL. Some of use have installed inline high pressure hyd filters in the PTO system.

The way my system and others work, is the suction filter is the input to the charge pump, which pumps abut 10 % of the VSP pump, somewhere around 5 GPM, and is running all the time. It is also used to charge and flush the pump to help keep it cool. This is the only filter in the system, and the other two hyd pumps pump out of the hyd tank which has only been filtered by the one filter. The VSP pump is used in a closed loop system, and if the wheel motors have a case drain, that fluid goes back to tank through a radiator system.

The point to make here is that the systems on our Power-Tracs, seem to work quite well, as I haven't heard of any failures attributed to contaminated hyd fluid. By the way, the Power-Tracs use 10W-30 or 40 motor oil for the hyd fluid. Some use synthetic motor oil. One of the reasons for the use of motor oils, is that one can find motor just about anywhere, and we usually have some around the house/garage.

Some of us have cut the filters apart, and found some stuff in them but nothing significant. Maybe bits and pieces of hose material. A gage on the oil filter is recommend to catch a clogged filter if it should occur.



I think we all understand that if a suction filter clogged up, that it could destroy a pump, so we change it out about every 100 hrs. Cost about $15.

Just some data from the Power-Trac people that might help others dealing with hyd.

The factory recommend (insists) that the filter on the PT400 series tractors be changed every 50 hours. That is about once a year for me.

 

[Transit]

Less than a 150 micron filter in the pump suction line is asking for trouble. It would be better off with a 150 micron filter in the suction line to the pump and a 10, 5 or 1 micron filter in the return line to the sump. If that filter were to clog the internal bypass would open and no harm done.

 

[Bob999]

Less than a 150 micron filter in the pump suction line is asking for trouble. It would be better off with a 150 micron filter in the suction line to the pump and a 10, 5 or 1 micron filter in the return line to the sump. If that filter were to clog the internal bypass would open and no harm done.

There are trade offs in most system designs. Variable displacement pumps are very susceptible to damage from dirt and debris and because of this PT has chosen to filter (10 microns) the suction intake for the charge pump which is a part of the variable displacement pump. They have chosen a large filter--rated at 60 gpm on larger machines I believe--and used large diameter hoses to connect between the reservoir and the filter and the filter to pump to minimize resistance to flow. PT also recommends very frequent replacement of the filter to minimize resistance to flow. PT uses multi-viscosity motor oil to minimize fluid thickening at low temperatures which would also be a greater problem with a suction line filter.

Eliminating the suction line filter would reduce the possibility of flow resistance creating sufficient suction that the pump cavitates and damages/destroys the pump. But eliminating the suction line filter will also increase the likelihood that the variable displacement pump will be damaged because of dirt and debris in the supply oil.

 

[oldnslo]

Some systems also use a pressure filter between the charge pump and the main VSP. These are more common on larger systems that also use the charge pump for implement lift or piloting other controls.

There is no one answer for where are how the filters are applied. Each OEM has there own method and most of them work as long as maintenance schedule is followed.

 

[SpringHollow]

On the 1850, there is a high pressure Schroeder filter on one of the circuits (I do not remember which one).

Just checked the manual. They call it a charging valve filter assembly.

Ken

 

[woodlandfarms]

Lift Tilt Dump Steering circuit Ken...

My question is how do those filter holders work. I never have understood the guage on the top. It says if you can't turn it while engine is running then filter is clogged... confusing to say the least.

 

[ponytug]

According to Terry this was an idea they tried out for awhile.

You can draw your own conclusions about, but I believe it is no longer included. I talked with Terry about adding it to the return line from the brake assembly (1XXX models) as this is the lowest pressure point for the least work, but there is also the additional parasitic HP load. By installing it on the turn/lift/curl circuit, the parasitic load is minimized, but so is the volume of oil filtered.

Personally, I came down on the keep the oil and connectors super clean and "use a filter cart" end of things.

All the best,

Peter

On the 1850, there is a high pressure Schroeder filter on one of the circuits (I do not remember which one).

Just checked the manual. They call it a charging valve filter assembly.

Ken