ISO 6117:2005

Overview

ISO 6117:2005 defines performance tests and general requirements for moulded elastomeric boots used as end closures on drum‑type hydraulic wheel brake cylinders. These boots prevent ingress of dirt and moisture that can cause corrosion or impair brake operation. The standard applies to plain and reinforcement‑insert boot types intended for use with non‑petroleum base hydraulic brake fluids (per ISO 4925) and to rubber compounds suitable for service temperatures from −40 °C to +100 °C.

Key topics and technical requirements

• Scope exclusions: ISO 6117:2005 does not specify chemical composition, tensile strength, elongation at break of the rubber, nor the adhesion strength between rubber and reinforcement inserts.
• Workmanship & marking: Boots must be free from blisters, pinholes, cracks and meet dimensional drawings. Manufacturer identification and optionally the mark “ISO 6117” should be moulded where design permits.
• Performance tests (selected limits and procedures included in the standard):
  • Resistance to fluid at elevated temperature: Immersion in reference brake fluid at 100 °C for 70 h. Acceptable volume change −15% to +15% and hardness change −10 to +10 IRHD; inspect for disintegration.
  • High temperature stroking: Cyclic actuation at 100 °C for 70 h; boots must show no flexure cracks through the wall and must fit tightly.
  • Low temperature stroking: Exposure to −40 °C to −43 °C followed by strokes; boots must not crack or come loose.
  • Tension set: After 70 h aging at 100 °C, tension set shall not exceed 75% (average of three specimens).
  • Heat resistance (static): 70 h at 100 °C; no cracking, hardness change −5 to +10 IRHD, and no tackiness.
  • Ozone resistance: 70 h at 50 pphm ozone and 40 °C under 15% stretch; no cracking or surface failure under 2× magnification.
• Sampling, packaging and test specimen preparation: Procedures and lot sampling frequency to be agreed between manufacturer and purchaser.

Applications and users

ISO 6117:2005 is used by:

• Brake component manufacturers and elastomer suppliers for design validation and production quality control.
• Automotive OEMs and tier‑1 suppliers specifying wheel cylinder boot performance for drum‑brake assemblies.
• Test laboratories and quality assurance teams performing compatibility, ageing and durability tests.
• Procurement and certification bodies referencing accepted test methods for non‑petroleum brake fluid systems.

Practical benefits include ensuring long‑term sealing performance, contamination protection, and compatibility with specified brake fluids across typical service temperature ranges.

Related standards

• ISO 4925 / ISO 4926 - non‑petroleum base brake fluids and reference fluids (compatibility)
• ISO 488, ISO 48 - rubber hardness measurement (ISO 48 referenced)
• ISO 188 - accelerated ageing and heat resistance procedures
• ISO 1431 - ozone resistance test method
• ISO 4928, ISO 7633 - related elastomeric boot standards for other fluids or temperature limits

Keywords: ISO 6117:2005, elastomeric boots, drum‑type wheel brake cylinders, non‑petroleum brake fluid, performance tests, heat resistance, ozone resistance, tension set.