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Hayes Nine lever bleed fitting

flat broke

Monkey
Nov 18, 2004
171
0
Long Beach, CA
Is the sliver aluminum fitting from Hayes required to bleed the HFX Nine brakes? Obviously I don't want to puke fluid out of the lever all over everything, but is the silver fitting a small check valve or is it just an adapter to get a hose into the bleed hole so that fluid can drain cleanly into a catch bottle for inspection for bubbles etc?

The syringe and hose isn't a problem, and I understand the procedure, but I was curious about the fitting.

My rear is a little soggy, and probably needs a fluid change, so if I need to buy the fitting b4 I start it'd be good to know.

Thanks in advance,
Chris
 

flat broke

Monkey
Nov 18, 2004
171
0
Long Beach, CA
I ended up with a fitting anyhow, so that I could run the hose and inspect for air bubbles etc. I got my front set sorted out fine, but the rear doesn't seem to want to bleed no matter how much fluid I run through it. I've seriously put upwards to 120ccs through it in a single bleed and it still felt spongy when I was done. The last time I finished up, by the time I was done with my test ride, I could pull the lever back to the bars. There was no fluid leaking anywhere, and the pads were dry etc. So it's gotta be pulling air in somewhere.

The caliper bleed fetting was tight, the hose connections are tight, and the only thing I can think is that the cheesey little bleed plug on the MC is letting air in somehow. No fluid gets out, but I'm kinda skeptical as to how well that plug should seal, or if it really needs to. It's a super loose fit when I put the fitting in for the hose to go to the catch bottle, and the plastic plug that goes in when you're riding feels like it's not very snug either. Does anyone have any input on how tight that plug should be? They have a washer/o-ring at the head, so I'm assuming it's supposed to be snug.

Thanks in advance,
Chris
 

Dartman

Old Bastard Mike
Feb 26, 2003
3,916
0
Richmond, VA
The inner liner in the hose may be leaking. Look for a kink in the line either under the cover at the lever or somewhere along the frame like at a zip tie. Bleed it a couple more times and you should find the leak as the weaker outer cover will pop covering you with fluid.

Or just replace the hose and try again.

Mike

edit: OR...draw back fluid from the caliper when bleeding. If you see a stream of small bubbles coming out your bleed screw threads maybe leaking by. But I'm betting on the hose.
 

flat broke

Monkey
Nov 18, 2004
171
0
Long Beach, CA
Thanks for the input.

So I take it I shouldn't really worry about the fitment of that plug in the MC? It stays in but just seems really sloppy. I'll pop all the zip ties and see if I can hose myself down in brake fluid ;) I don't have a problem buying a new line, but hate taking the part pushing route to fix stuff. With my luck, I'd buy the line and mine would be fine.

Every time I pulled back on the syringe after connecting the hose, I'd get one or two bubbles, then it would pull clean. However, after pushing a good amount of fluid through with no bubbles (30ccs), when I'd go to tighten the bleed fitting down it seems like I would always instantly see bubbles again. I'm going to pull the bleed fitting and wrap it with teflon tape to see if that cures the bubbles when tightening issue.

While I'm asking a bunch of questions, the Hayes manual says to stroke the lever while pushing fluid after I've cleared the caliper of air. But when I read online, no one mentions this step. What is the consensus on cycling the lever while pushing fluid?

Thanks in advance,
Chris
 

Dartman

Old Bastard Mike
Feb 26, 2003
3,916
0
Richmond, VA
Yeah the Hayes techs snap the lever when they bleed brakes. They give it a gentle squeeze (so the hose doesn't pop off) and let it snap back to shock loose bubbles from the system. Seems to work for me.
 

talusslope

Chimp
Apr 6, 2007
67
0
sst, WA
You might also try taking the whole brake off of the bike and hanging it when you bleed so as to be able the get rid of any bubbles that could be hiding in the bends of the hose.