hydraulic filter terminology

[washita]

the hydraulic filter located on the suction side of the tank, what is the correct/proper terminology for this filter? is it a suction filter, a pressure filter, or a return line filter (which I doubt) my BIL claims it is not a high pressure filter because it is before the pump, but I do not agree because if it was a low pressure filter ie:return line filter, the pressure differential (bypass relief valve) would not allow effective filtration of the oil to the pump. If anyone can clarify this issue give me some feedback

 

[Willl]

Return, low pressure, just before pump.

 

[MossRoad]

The filter is between the tank and the input side of the pump. It sucks fluid out of the tank, through the filter, and into the pump to make up for losses in the charge section of the variable volume pump that drives the wheel motors. That's how it was explained to me by the distinguished members of the Power Trac forum.

 

[J_J]

It is definitly a 10 micron filter used as a low pressure suction filter. The VSP pump have to be extreamly clean. This is the filter that the charge pump uses to keep the VSP charged with fluid to about 350 psi, and also flushes out the heat from the case of the VSP pump, and then goes through a fan powered radiator system The charge pump draws about 10 % of the max flow used by the closed loop hyd system used on the Power-Tracs. They have been using this setup for at least 20 years. If the filter should load up with debris, the bypass would let some fluid flow, but not filtered oil. We also use 10W-40 motor oil as the hyd fluid, and has been most suitable for what we do.

 

[Bob999]

It is under suction as installed in a PT. PT provides a low pressure filter as OEM--the same type of filter typically used on return lines. I have a vacuum gage on mine and at start up at 70 degrees or so I will see 20" vacuum on the gage. Once the hydraulic fluid is up to operating temperture the vacuum drops to 3-5" vacuum.