kpke
Veteran
Brake help please. I'm almost ready to start this project bike but would like to have front brakes available in case it runs.
Short version is front MC won't pressurize and little bubbles come up thru the little hole in the base of the MC. All parts are fresh rebuild or new. Long version below.
From my notes and a post on the RZ forum (with no response)...
11/9/20
Yesterday still having troubles with getting pressure in the front brakes. The rear is holding up fine.
Here is a nice diagram of this type of MC.
I think the calipers are not leaking. There is no fluid dripping off after 2 days. Earlier that fluid was (more I think) a result of opening the bleed screw. I am getting bubbles coming up into the reservoir. www studies indicate this is a MC problem. Unfortunate because I used a Yamaha rebuild kit on this thing.
I’ve adjusted the lever adjust screw all the way in to get max throw to no avail. Removing the splash plate on the bottom shows the bubbles coming out of the tiny hole closest to the lever. Next I’m going to take the bike off the lift, put it on the side stand, turn the bars full left, hoping to get any high spot out of it. I don’t think this will help.
Then I suppose I’ll change out the MC/lever assy to a 2005 R6 one I have in stock.
Anyone know what to use to purge the DOT 4 out of the R6 MC before putting the DOT 5 in? Alcohol?
Edit: I’ve tried this trick a few times to get air bubbles to purge up. It has not helped.
Short version is front MC won't pressurize and little bubbles come up thru the little hole in the base of the MC. All parts are fresh rebuild or new. Long version below.
From my notes and a post on the RZ forum (with no response)...
11/9/20
Yesterday still having troubles with getting pressure in the front brakes. The rear is holding up fine.
Here is a nice diagram of this type of MC.
I think the calipers are not leaking. There is no fluid dripping off after 2 days. Earlier that fluid was (more I think) a result of opening the bleed screw. I am getting bubbles coming up into the reservoir. www studies indicate this is a MC problem. Unfortunate because I used a Yamaha rebuild kit on this thing.
I’ve adjusted the lever adjust screw all the way in to get max throw to no avail. Removing the splash plate on the bottom shows the bubbles coming out of the tiny hole closest to the lever. Next I’m going to take the bike off the lift, put it on the side stand, turn the bars full left, hoping to get any high spot out of it. I don’t think this will help.
Then I suppose I’ll change out the MC/lever assy to a 2005 R6 one I have in stock.
Anyone know what to use to purge the DOT 4 out of the R6 MC before putting the DOT 5 in? Alcohol?
Edit: I’ve tried this trick a few times to get air bubbles to purge up. It has not helped.