Shimano instructs to insert the sharp end of the "oil stopper" to bleed the brakes:

"The other end" of the oil stopper

What is this for? I would expect that the oil should just flow from/to the funnel when pumped into the system with the syringe from the caliper bleeding screw. The other, wide end of the oil stopper, with the o-ring, is obviously needed to prevent oil flowing out when the funnel is being unscrewed from the brake lever; this is clear. But why does one need to insert the sharp end?

  • A guess is there are two different funnel/stoppers versions (old/new maybe). One the narrow end is the stopper, the other the wide end. Cost of changing drawings for something so obvious to the user is not worth it.
    – mattnz
    Commented Dec 18, 2022 at 5:04
  • @mattnz my question still is - what is the purpose of inserting the sharp end of the stopper into the funnel during pumping the oil from the caliper. Commented Dec 18, 2022 at 12:55
  • 1
    I think this is old information. Current funnels do not have this feature.
    – Noise
    Commented Dec 19, 2022 at 20:50
  • 1
    – Noise
    Commented Dec 19, 2022 at 20:51
  • 1
    Possibly this keeps the stopper in place so as not to get mislaid, without blocking the flow. The newer funnels allow the stopper to be clipped to the side out of the way.
    – Noise
    Commented Dec 19, 2022 at 20:53

1 Answer 1


When you want to remove the funnel from the brake lever, you put oil stopper into funnel where the oil goes out. It blocks the oil exit, so oil in the funnel won't spill.

Please note that you'll only insert it when removing the funnel - otherwise oil won't go into levers, obviously.

Wide end is not to be inserted into funnel - you'll only use the "sharp end" to block the funnel.

  • 2
    This is incorrect. The wide end of the oil stopper, supplied with the small rubber O-ring, is to be used to block the funnel when removing it from the handle. The sharp end does not block the flow. If you do not have a funnel at hand to try that yourself, see the manual SI-0061A-002-00 (from which the image is taken). Commented Dec 17, 2022 at 17:52
  • You two might be looking at different examples - that there's an O ring designed into the end implies it is intended to seal against something. Perhaps photos might clarify this.
    – Criggie
    Commented Dec 17, 2022 at 20:17
  • 1
    Agree that looking at the manual SI-0061A-002-00 this answer is incorrect
    – Swifty
    Commented Dec 20, 2022 at 21:43

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

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