Brake squeal is usually friction-induced vibration. On crane brakes, it often occurs when linings are glazed from heat, contaminated, or made from a friction material not well matched to the brake and duty cycle. Misalignment, loose mounting hardware, worn pins/bushings, and excessive air gap can amplify vibration and turn normal friction into audible noise. Disc surface condition matters too—scored or uneven discs can trigger squeal and accelerate pad wear.
To reduce squeal, start with basics: verify tight mounting, correct alignment, and OEM-specified air gap/clearance. Inspect friction material for glazing, cracking, or oil contamination and replace if needed. Ensure the brake wheel/disc surface is within specification and not heat-damaged. Avoid “quick fixes” like lubricating friction surfaces—this reduces braking torque and creates serious safety risk. For persistent noise, use the correct OEM lining grade and consider system resonance (mount stiffness and drivetrain vibration), which can require mechanical tuning.