Industrial brakes on cranes, conveyors, and winches are safety-critical devices. They don’t just “break”—they degrade slowly until they fail to hold a load or release properly. The difference between a routine pad change and a catastrophic load drop is almost always preventive maintenance (PM).
This article provides a practical maintenance schedule for YWZ13 electro-hydraulic drum brakes and SH hydraulic fail-safe disc brakes. We break it down into inspections that operators can do and tasks that require technicians.
A technician performing a clearance check on a drum brake with a feeler gauge.
1) Daily / Shift Inspection (Operator Level)
Goal: Catch obvious failures before starting work. No tools required.
- Visual Check: Is the brake mechanically intact? No loose bolts lying on the floor?
- Test fonctionnel :
- Lift a small test load just off the ground. Does the brake hold it steady?
- Does the brake release smoothly without strange noises (grinding/squealing)?
- Temperature Check (Touch/IR): Is the thruster motor or brake wheel abnormally hot after a few cycles? (Compare to yesterday).
- Leak Check: Any fresh oil puddles under the thruster or hydraulic caliper?
2) Weekly Inspection (Technician Level)
Goal: Verify adjustments and lubrication.
- Clearance Check:
- Drum (YWZ): Check shoe clearance at center. Is it equal left/right? (e.g., 0.8mm each side). If not, adjust the equal-retreat stop bolt.
- Disc (SH): Check air gap. Is it within spec (e.g., 1.0mm per side)? If too wide, pads are worn or retraction springs are weak.
- Lining Thickness: Visual check. Is there plenty of material above the rivets/wear line?
- Pivot Freedom: Do the arms move freely? If pivots are stiff, grease them (1-2 pumps only).
- Spring Length: Is the main torque spring length correct according to the scale/manual? (Springs relax over time).
3) Monthly / Quarterly Inspection (Deep Dive)
Goal: Identify wear trends and potential component failures.
- Bolt Torque: Check mounting bolts (base-to-foundation) and thruster mounting pins. Vibration loosens them.
- Thruster Oil: Check level (sight glass or plug). Check condition (is it black/burnt? Milky/watery?). Replace if needed.
- Disc/Drum Condition: Inspect friction surface for deep scoring, heat cracks, or glazing. Clean with solvent if oily.
- Linkage Wear: Wiggle the arms. Is there excessive play in the pivot pins? (> 1mm slop means bushings are shot).
- Electrical Connections: Open the terminal box. Are wires tight? Is the cable gland sealing against dust/water?
- Débrayage manuel : Test the hand lever/pump. Does it open the brake? Does it fully return when released? (Crucial safety check).
4) Annual Overhaul (Major Maintenance)
Goal: Restore to “near-new” condition.
- Replace Linings: Even if not fully worn, old linings can become hard/brittle.
- Replace Seals: Re-seal hydraulic calipers or thrusters if weeping.
- Change Thruster Oil: Drain, flush, and refill with fresh hydraulic fluid (correct viscosity for season).
- Brake Torque Test: Perform a static load test (125% load) to verify holding capacity after reassembly.
5) Common Neglected Items
| Component | What Gets Forgotten | Consequence |
|---|---|---|
| Auto-Aligning Device | Adjustment nut loosens. | Uneven shoe wear (tapered linings). |
| Breather Plug | Gets painted over or clogged with dust. | Thruster builds internal pressure/vacuum; sucks in water or leaks oil. |
| Pivot Pins | Grease fittings painted over; never greased. | Arms seize; brake drags; thruster burns out. |
Need a customized maintenance plan?
We can provide a model-specific maintenance manual for your YWZ or SH brakes, complete with wear limit dimensions, oil specifications, and torque values. Don’t guess—maintain by the book.