A brake that won't hold the table stationary under cutting load is a safety issue. The W&B brake system has two main components: the hydraulic brake cylinder (WB25452) and the friction brake shoes (KB1124). Both are wear items and both are common failure points.
Symptoms
- Table drifts under load: The table moves slowly when it should be stationary — the brake is not applying enough clamping force
- Slow table stopping: The table takes noticeably longer to come to rest after disengaging the clutch
- Hydraulic fluid visible around brake area: Leaking brake cylinder — the seals have failed
- Grinding or squealing when brake applies: Brake shoes are worn to the backing plate, or contaminated with oil
Check the Brake Cylinder (WB25452)
The brake cylinder is a hydraulic actuator that applies clamping force to the brake shoes. Failure modes:
- External leak: Visible hydraulic fluid around the cylinder — seals have failed. Replace the cylinder.
- Internal bypass: No visible leak, but braking force is reduced — the piston seals are bypassing internally. The cylinder feels "spongy" when the brake is applied. Replace the cylinder.
- Sticking: The cylinder does not fully extend or retract — corrosion or debris in the bore. Rebuild or replace.
Check the Brake Shoes (KB1124)
Brake shoes are the friction surfaces that contact the brake drum. Failure modes:
- Worn friction material: Measure thickness — replace when worn to minimum. Sold as a matched pair.
- Oil contamination: If the brake cylinder is leaking, hydraulic fluid contaminates the shoe friction material. Contaminated shoes will not hold — they must be replaced (not cleaned). Fix the cylinder leak first, or the new shoes will be destroyed quickly.
- Glazing: The friction surface has become smooth and glassy from overheating. Shoes need replacement.
Order Brake Parts
We source both components direct from W&B UK:
- WB25452 — Brake cylinder (8 orders on file — our second most-ordered part)
- KB1124 — Brake shoes, 1 pair (7 orders on file)
Related Parts
- WB25452 — Brake Cylinder
- KB1124 — Brake Shoes