Sticky brakes

[Geoff-at-far]

I don't ride my 79 CBX as often as I like. I have had the bike two years. I rebuilt the calipers and put SS lines on when I rebuilt the calipers. Now two years later the brakes are sticky. I've pulled them apart again and found that the pistons have some pitting and the inside of the bore doesn't look great. Is it worth trying new pistons or any other suggestions. Thanks, Geoff.

[ajs350]

Geoff
Before buying new pistons I'd try some light wet and dry paper (1000 grit) on both the bores and the pistons. I did this on my 79 and the stickyness was resolved.
Ross

[Jeff Bennetts]

Make sure the tiny orifice in the master cylinder is clear, if not it hold pressure and not release the calipers, also make sure the grove in the caliper where the square shouldered seal sets is completely clean.

[Larry Zimmer]

Jeff, the 'polishing' with 1000 grit will likely work. One word of caution when doing it: move around the piston with the paper when polishing. Do not move the paper along the 'axis' of the piston. While it may not see noticeable, the 'cutting' of the surface can create a leak if it is along the axis of the piston. (In the same direction as the piston movement.) Same thing applies when cleaning fork tubes while installing new fork seals. Always do the polishing at 90 degrees to the movement. (Same goes for cylinder honing, etc.) Also, use some brake fluid as a lube for the brake piston polishing; and, clean well afterwards. Should work good.

[Geoff-at-far]

Thanks Ajs350, Jeff Bennetts, and Larry Zimmer. The sanding with the 1000 grit worked well, stickyness is gone. Also, I know there are many ways to skin a cat, when bleeding my brakes a run 1/4 inch tygon tubing attached with hose clamp from bleeder screws back to master cylinder and just pump the fluid through and back to the master while frequently tapping on horizontal section with a dead blow hammer. I hold the hose in place with zip ties.Takes about ten minutes after your set up. Anyways, thanks again for the tip.

[ajs350]

You're welcome Geoff. Glad you got it all sorted and are back riding.

[michelsmith]

What pads did you use?