79R100RT Front End Shudder

[Bman]

Help!!! The front brake calipers do not release.
The shuddering in first gear start up is unnerving.
Can anyone shed some light on how to adjust the front calipers to return completely?

[kbasa]

Could be a couple things.

The pistons in the caliper may be rusted into a position that prevents them from retracting back into the calipers.

Your master cylinder may have some goo in the brake fluid return that prevents fluid from coming back into the reservoir, alleviating pressure on the calipers.

I had a Honda one time that turned out to need a new master cylinder because the return was clogged. For me, it came from poor brake fluid maintenance.

[BMWRich58]

Could be a couple of things...The pistons in the caliper may be rusted into a position that prevents them from retracting back into the calipers.

Absolutely

The rust/grime deposits build up and settle behind the pistons in the caliper (lowest point in the braking system) and prevent the pistons from returning back to their normal position. Just one of the many reasons brake fluid changes and maintenence are necessary.

[James.A]

While I do not own a disc brake motorcycle, I experienced a similar brake-stuck-on episode with a chevy van with front discs. Since the physics of disc brakes is similar the experience may be useful. In my particular situation, the inside of the rubber brake hose was deteriorated and swelled up. It essemtially functioned like a check valve. If you remove the caliper and the piston can be collapsed with a clamp, look further up line in your brake system.

[BMWRich58]

While I do not own a disc brake motorcycle, I experienced a similar brake-stuck-on episode with a chevy van with front discs. Since the physics of disc brakes is similar the experience may be useful. In my particular situation, the inside of the rubber brake hose was deteriorated and swelled up. It essemtially functioned like a check valve. If you remove the caliper and the piston can be collapsed with a clamp, look further up line in your brake system.

Yes sir,
absolutely,
there can be a number of reasons for "Brake Failure".