Unexplained Fluid Pressure

[Guest]

So today I was working on my bike and while switching out the secondary gear oil and final drive oil I tried to roll the bike forward and I realized that the brakes were locked up. I tried putting a feeler gage between the rotors and the pads and it wouldn't go. I then felt the brake lever and it was unusually tight. I then unscrewed the bleeder a bit, and just a drop came out. I then immediately tightened up the bleeder. The fluid was a bit low, but still within the limit. I topped it off, and took it about 10 miles. It hasn't had a problem since.
Does anyone know what would have caused this and what I should do from here?

[tkent02]

What maintenance have you done to your brakes?

[Steve]

First of all, the only time you will be able to get a feeler gauge between the pads and the disk is when you first install them and have not yet squeezed the lever.

As tkent asked, what (if any) maintenance have you done to the brakes?

It appears that the compensation port in the master cylinder is plugged. This will not allow fluid in the brake lines to vent into the master cylinder when the brakes are not applied. A thorough cleaning of the master cylinder should take care of that.

.

[tkent02]

A thorough cleaning of the master cylinder should take care of that.

.

Not so fast, clean the calipers too, and lose the ancient hoses. Crud from the calipers can migrate to the port and clog it again.

Having the front wheel lock up unannounced is a crappy way to dump a bike.

[nastyjones]

I disassemble the calipers & master & run everything through my ultrasonic cleaner. It's not just for carbs you know.
Everythings clean as a whistle.

[Nessism]

Crud in the system has blocked the small return port in the master cylinder. The only way to fix this and assure it doesn't come back is as Tom suggests, with maintenance. Tear down the calipers and master cylinders and clean them, and replace all the brake lines. Lack of maintenance can get you killed on a motorcycle. Good thing you caught this in time before it dumped you on your head.

[bbjumper]

Crud in the system has blocked the small return port in the master cylinder. The only way to fix this and assure it doesn't come back is as Tom suggests, with maintenance. Tear down the calipers and master cylinders and clean them, and replace all the brake lines. Lack of maintenance can get you killed on a motorcycle. Good thing you caught this in time before it dumped you on your head.

DITTO !!!

I had that happen to me on the Slab at around 75. Lucked out and didn't loose the bike. Released the pressure in the lines and backed the pads away from the smoking hot rotors and gingerly got her home with the rear brake.

After new rotors rebuilt calipers including new pistons, rebuilt master cylinder, new stainless lines and pads, good as new and best of all I have complete confidence in the bike's brakes again. I luckily got the lesson without paying the price for the education.

Good advice..

[Nessism]

DITTO !!!

I had that happen to me on the Slab at around 75. Lucked out and didn't loose the bike. Released the pressure in the lines and backed the pads away from the smoking hot rotors and gingerly got her home with the rear brake.

After new rotors rebuilt calipers including new pistons, rebuilt master cylinder, new stainless lines and pads, good as new and best of all I have complete confidence in the bike's brakes again. I luckily got the lesson without paying the price for the education.

Good advice..

This post should be a sticky! Glad you are okay.

[bbjumper]

This post should be a sticky! Glad you are okay.

Thanks, sometimes you get one for free.

[Triam]

Yeah, I hadn't really done anything on the braking system. I guess I'll add that to the list of things to do to this bike.

[bbjumper]

Yeah, I hadn't really done anything on the braking system. I guess I'll add that to the list of things to do to this bike.

Yea, your already in an environment that is inherently riskier than cagers. Just a good idea in my book, not telling anybody what to do but you have control of the maintenance status of your ride.

Cheers.