ISO 4927:1978

Road vehicles — Elastomeric boots for drum type hydraulic brake wheel cylinders using a non-petroleum base hydraulic brake fluid (Service temperature 120 degrees C maximum)

Specifies performance tests for moulded rubber boots used at end closures on drum type brake cylinders. These boots prevent the entrance of dirt and moisture which could cause corrosion and otherwise impair wheel brake operation. Applies to boots of both plain and reinforcement insert types. Requirements relating to chemical composition, tensile strength or elongation at break of the rubber compound are not included.