DFE is able to offer a no-squeal warranty because of a proprietary
design feature that virtually ends routine squeal problems for users
of Dover's dual disc or single disc brakes. The 'fix' comes after much
research and cooperation with the dissatisfied brake customers of several
This warranty is in addition to our standard warranty. It applies to
brakes purchased after April 2, 1999.
The No-Squeal Warranty:
Dover Flexo Electronics, Inc. (DFE) warrants our dual disc and single
disc tensioning brakes against annoying squealing noises when installed
according to our instructions. This warranty shall be void if non-DFE parts
are used in the brake or if the brake has been contaminated with liquid,
solid, or powder applied to the brake discs or friction
Conditions of Dual Disk Brake Installation for No-Squeal Warranty to be Valid
The brake mounting surface must be rigid and strong enough so it
doesn't deflect when loaded by brake torque.
The shaft must be straight. (Bent shafts cause disk runout.)
The shaft must not have noticeable end-play.
The shaft bearings must be in good condition, with no noticeable
free-play or noise.
The shaft diameter must be properly matched to the brake bore. (A
loose fit can cause balance problems and disk runout.)
The shaft must be perpendicular to the brake mounting surface to
within .04"(1mm), measured at the end of the shaft.
The set-screws fastening the disk-hub assembly to the shaft must
be tight. The disk-hub assembly must not move on the shaft.
The actuator plates must be centered between the disks and be parallel
to the brake mounting surface.
All mounting bolts must be tight.
The friction surfaces of the disks and friction pads must be clean
and free of oil or any other lubricant.
The friction pads must installed with the friction surface against
the disk, and the steel backplate against the air cylinder.