Question about bleeding Shimano brakes with a plastic funnel vs the metal one

I was at a co-op shop in Portland last week and the mechanic there swore I was wasting time using the plastic bleed funnel from the kit, said it lets air bubbles sneak back in. Has anyone else noticed a real difference between the two or is that just old-timer lore?

3 comments

3 Comments

mason7987d ago

Broke my plastic funnel on the third bleed anyway. Dropped it on the concrete floor and it cracked right down the side. Air bubbles leaking back in? Man I couldnt even get the thing to seal right from the start. Switched to the metal Park Tool funnel and yeah its way easier. No wobble. Stays in place. But honestly Im still bleeding like a drunk surgeon so maybe the tools dont matter that much.

seth_carr7d ago

Gotta push back a little here man. Ive had that Park Tool metal funnel for years and it works fine but the plastic ones arent all garbage. You probably just got a bad one or it was sitting in the sun too long. The key is to push the funnel down hard into the lever or caliper and make sure the o-ring is clean and lubed up. If its dry or dirty itll never seal. Also you gotta hold the funnel steady with one hand while you pump the lever with the other. The metal one is nice but it wont fix sloppy technique.

hugo_cooper5d ago

Man my bleeding technique is so bad I could probably mess up a bleed even with a solid gold funnel. I've used both plastic and metal and honestly the biggest difference is how hard I cuss when I drop them. The plastic one shattered on my garage floor and I just stood there staring at it like it personally insulted my ancestors. But hey at least the metal one doubles as a paperweight for when I get too frustrated and need to take a break.