Snowplow Hydraulic System Maintenance

The majority of snowplow operational problems are caused by bad oil in the hydraulic system. Hydraulic oil should be change every year for best performance. Select Hiniker Cold Flow Hydraulic Oil or an equivalent oil that meets military specification 5606, for plowing in extremely cold temperatures.

To change hydraulic oil, disconnect the electrical wiring harnesses from the snowplow power unit and uncouple the hydraulic lines. Unbolt the power unit from the plow, and remove it to a clean working area that can capture any spilled oil.

Carefully unbolt the oil reservoir from the power unit and discard old oil. Purge old oil from the angling cylinders by forcing rods to retract.

Clean the suction filter at the pump inlet and wipe any metal shavings off the magnet on the pump.
Re-attach the reservoir onto the power unit and re-connect the power unit on the snowplow before adding new hydraulic oil.

Re-attach hydraulic hoses and electrical wires at the correct locations on the power unit.

Pour hydraulic oil into the power unit reservoir until the reservoir is half full. Angle the plow full left or right to fill the angling cylinder with oil, then add more oil until the reservoir is about ¾ full. Do not overfill the oil reservoir.

Cycle the plow left and right and up and down to purge any air trapped in the hydraulic system.

Check the oil level with the plow on the ground. Add oil to the fill line, if necessary, but do not over fill the reservoir.