Soft Front Brake Pull
- Thread starter glider.
- Start date
RibEye
Senior Member
The way to distinguish between air in the lines and what I describe above is the feel at the contact point of the brakes. In a case such as I describe above, when the braking contact point is reached (the brakes come up to contacting the disc), the action is then nice and hard and positive, like normal. When there is air in the lines, the feel is more spongy. Unless you have felt both conditions personally, you may not be able to distinguish them. Always eliminate the possibility for air, or some other contaminant, in the lines as a matter of corrective course.
Also, in a case like mine, you may find that once you have pumped the pads up to the discs initially, on a ride where regular application of brakes is required (in town for instance), the brakes tend to remain pumped up to reliable operation. If left un-actuated for a longer period, they may require pumping up again. Air in the lines does not allow pumping the brakes up to be effective between actuations. The loss of "pumping up" effectivity, with dirty pistons, is due to the relatively weak retraction that the seals perform over time. The seals will pull the pads back from the discs too far, hence, the extra lever required to reach the discs. Clean pistons won't catch on the seals. Normally, the pads only retract as far as any eccentricity in the discs will push them once they are released. HD brakes do not have retraction springs. That is why, on very true discs, pads tend to hiss and chirp when not being applied (kind of riding loosely on the discs).
Never ride a machine with unreliable brakes. Period.
Enjoy,
Rich P