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Rear Brake Seizing
Posted: Sun Jun 15, 2008 10:51 am
by twinegar
The rear brake seized in the driveway after the first test ride. I rebuilt the caliper and it did it again and I then moved to the master cylinder and noticed that the pin that unites the cylinder shaft to the brake lever is missing. would this account for the brake pads not releasing? Is the brake pedal returning to the park position and pulling the cylinder shaft back out what it takes to release the brake?
Posted: Sun Jun 15, 2008 8:19 pm
by steve murdoch icoa #5322
It makes sense to me that the brake fluid is staying under pressure in the brake line and caliper if the master cylinder piston is not returning to the static? position.
Posted: Wed Jun 18, 2008 10:23 am
by twinegar
I took the fluid feed tube off and see 2 ports. The feed port is open and flowing but the return port almost looks like there is no hole at the bottom of the port. I am going to use a micro bit to clear it unless someone has a better idea. I have done this on a couple of my other bikes but never on a rear master. I guess they all work the same?
Posted: Wed Jun 18, 2008 10:30 am
by twinegar
Never mind, I found another post dealing with this.
Posted: Sat Jun 21, 2008 2:54 pm
by alimey4u2
Blocked compensator port me thinks...
Posted: Sat Jun 21, 2008 4:08 pm
by twinegar
It was. I used a #80 drill bit and cleared the hole. I wonder why Honda doesn't make a larger return hole. I enlarged the hole on 2 of my CB750's while I had them apart and it works fine. Maybe they use a tiny hole so when brake bleeding with the cap off fluid doesn't squirt all over the place.
Posted: Sat Jun 21, 2008 5:20 pm
by alimey4u2
I think a tiny hole is to control the speed of return to rest of the pucks ( hence brake pads) using hydraulic dampening.
Master cylinder
Posted: Tue Jul 08, 2008 4:42 pm
by Dave Ditner
The reason for the small hole size of the compensating port is pressure generation. Sizewise the master cylinders are marginal. The larger the hole the farther down the bore the piston must be to start generating pressure, and they can't afford the wasted space.
Re: Master cylinder
Posted: Tue Jul 08, 2008 5:29 pm
by alimey4u2
Dave Ditner wrote:The reason for the small hole size of the compensating port is pressure generation. Sizewise the master cylinders are marginal. The larger the hole the farther down the bore the piston must be to start generating pressure, and they can't afford the wasted space.
Thanks for that Dave, makes perfect sense....
Ps. We miss you...
