Lossless Hydraulic Filter Change

[Roadworthy]

I have read you can connect a shop vac to reduce fluid loss during hydraulic filter change, unfortunately nobody tells how. The filler cap on my L2501 happens to be one inch NPT threaded. I used a one inch socket to male NPT PVC connector, a short piece of one inch PVC, and a PVC socket coupling. I took a couple turns of biseal tape around the coupling and it fit my shop vac hose for a tight friction fit. I replaced my Hydraulic and HST filters and probably lost less than a quart of fluid between the two. My shop vac was whining to beat the band but seemed to have suffered no permanent damage.

 

[Smokeydog]

That’s a neat trick I’ve read several folks use. On my tractors the HST is above the tank or transmission level so the oil loss is minimal at 200hours. At 400hours the oil, hydraulic and HST all get changed so oil loss is not a problem. Can see the technique be helpful changing a dented hydraulic filter or damaged lower line.

I wonder if using the vacuum technique back flushes the filter, particularly the hydraulic suction filter back to reservoir?

Some engine oil filters have anti-drain back valves. Not sure about Kubota hydraulic filters.