PLUG 1/8″BSP EH250/500

Edwards EH250 or EH500 pump is a Roots vacuum booster . It has oil inside to lubricate the bearings and gears. That oil needs to be changed from time to time.

To change the oil, you need to open two holes. One hole is to let the old oil drain out. That is the drain plug. The other hole is to pour new oil in. That is the filler plug.

This plug seals both of those holes.

According to the official Edwards EH250/500 instruction manual, these pumps have two oil reservoirs:

1. The hydrokinetic drive/gearbox (the main oil reservoir)

2. The shaft-seal reservoir

Each reservoir has its own oil filler plug and oil drain plug . This exact plug is used for those ports. The manual shows that you must remove the “oil filler-plug” before draining the oil .