Hydraulic pump question

[SleepyFarmall]

I am repairing a hyd wood splitter that has been in the fence row for years. It never had a filter on the hyd line and I am going to install one. The question is, does the return line supply the pump by gravity or does the pump suction the fluid. If gravity is the force then mounting the filter will require the filter to be positioned near the ground since the pump is also mounted low. Don't want the filter to drag on a stump or limb on the ground. Thanks for help, Michael

 

[Tom from Buckeye Lake]

Generally there is a strainer in the suction line. Return oil is not under pressure and if a filter was installed in that line, it could reduce flow and speed of cylinder.

 

[Steve@Advance]

The pump is capable of drawing oil up once it is primed.

Typically there is a suction strainer inside the tank. It is just a fine mesh wire strainer to protect the pump from damage.

The filter goes in the return line, the line from the valve back to the tank.

 

[stevieb49829]

But the return-to-tank line is usually where the filter is installed. With clean oil and a new filter, there should be very little restriction showing up as a slow return of the cylinder. Otherwise you are looking at installing a high pressure filter in the pressure side, or restricting the suction line with a filter, which is a big no-no. That's why they use a screen in that circuit, like Steve explains.

 

[SleepyFarmall]

Thanks for the replys.
This is a home-built splitter and doubt there is a strainer in the tank. I'm skeptical about what's in the reservoir. New pump installed and don't want to ruin it. I think I'll install the filter and see how it operates. If it's too slow I can remove it but will have greater confidence in the condition of the fluid at that point. Thanks, Michael

 

[Jim.ME]

You could get a wye strainer at a plumbing supply (they are available with different mesh sizes) and install it in the suction line at the tank outlet (get the same size or larger than the tank outlet fitting to avoid restriction). Then install a filter in the return line between the valve and tank.