Every time we lose our bleed nipple cap we manage to get mud all over the nipple. Next time we bleed our brakes it ends up introducing dirt into the brake fluid which decreases the quality of the bleed.

Here's a replacement bleed nipple to sort that out for you.

Note: Please be careful with these when you take them off for a bleed. If you are a bit too rough you can break them. Sadly we couldn't find a supplier which offered more robust ones. Other than breaking a little easier than we would like, we've been using these for quite a while and they work well!