Professional Civil, Structural and Environmental Engineers in Harlow

Concerned that this is causing customers unnecessary and unplanned expense, Imperial Engineering has investigated early bus brake caliper failure in detail and found four specific caliper-related faults that can be rectified. Poor seal between caliper and actuator This typically occurs after changing a spring brake when the unit has not been correctly refitted, preventing a seal to be formed. Water ingress then takes place, causing corrosion leading to seizure of the caliper. Missing sealing caps Sealing caps, also known as ‘witches’ hats’ or adjuster caps, are intended to provide a seal for the caliper to prevent water ingress during service, or when a vehicle is being power washed. As well as causing water-related damage, missing sealing caps will also result in MOT failure. Seized caliper bearings Dirt and water ingress due to damaged or missing seals can also cause the caliper’s bearings to seize, resulting in component failure. Torn caliper boots Often caused by heat damage or road debris, tears and splits in a caliper’s protective ‘boot’ can be easily overlooked. Over time, a damaged caliper boot will lead to dirt build-up and water ingress in the disc brake’s internal mechanism causing premature failure. Fitting a replacement boot, which costs around £50, is an effective solution to this problem. Imperial Engineering has a wealth of disc brake system knowledge and is pleased to support operators with technical advice and guidance.