Place the filter in the solvent tank. You should wear rubber gloves throughout the entire procedure. Place the filter gently in the tank; do not drop it.
Turn on the solvent pump. The switch should be located on the side of the tank. Allow the solvent to flow through the nozzle.
Clean the filter. Place the filter beneath the solvent and rinse it off thoroughly. While rinsing, use your toothbrush to scrub off dirt and debris. The solvent will dissolve dirty oil clogging the filter, so allow it to run freely over the entire filter medium. When cleaning is complete, turn off the solvent feed. Shake the filter to remove excess solvent.
Pour 1 gallon of hydraulic fluid into a 2-gallon bucket. Be careful not to splash it.
Put your filter inside the bucket and swish it around in the hydraulic fluid for about 5 minutes. This will neutralize any solvent left over from the cleaning process.
Reinsert the filter according to the instructions on your appliance. The used hydraulic fluid in the bucket can be recycled at most major gas or service stations.