Armstrong S-25 PumpRecently replaced a leaking bearing assembly on my Armstrong S-25 pump. The previous one required oiling, the new one is the permanently lubricated MF/BF model. I look forward to not having to lubricate the bearing assembly, but what about the motor? The original manual that came with the pump indicates that the motor has oil cups that must be lubricated at the start of each season. However I don't see the cups, nor any inlets to add oil to. How would I go about lubricating the motor?

  • Sometimes the oil ports are small holes at each end of the motor. Some manufacturers pug with plastic some are just left open. – Ed Beal Dec 16 '17 at 16:48
  • Right now the boiler is running (still cold outside), but I have an identical motor in storage (it was making grinding noise and I replaced it couple years ago). I removed the brackets for close inspection, and just can't find any ports to add lubricating oil, capped or not. Now, the manual states to add oil to motors with oil cups (suggesting that some may not have them). Still, I recall the old motor grinding, and would like to avoid same with the new one. Puzzled. – Roz Dec 16 '17 at 18:57
  • The new motor probably has double sealed bearings these have no way to add fresh lubrication, on large motors I usually order double sealed and pull 1 side so they can have grease added but these motors have grease ports to add grease. – Ed Beal Dec 16 '17 at 21:45
  • Thank you for replying. I guess between the permanently lubricated bearing assembly and the motor, this makes my pump truly maintenance free :) Just sit back and watch it outlive me... – Roz Dec 16 '17 at 23:21

That black plastic circle is where the oil/lubricant should go. Twist to loosen it, then pull it out.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.