ISO 6314:1980

Overview

ISO 6314:1980 - Road vehicles - Brake linings - Resistance to water, saline solution, oil and brake fluid - Test procedure defines a laboratory method to evaluate how contamination by water, saline solution, oil or brake fluid affects the strength and shape of organic brake linings. The standard applies to drum brake linings and disc brake pads intended for road vehicles and prescribes controlled exposure, measurement and comparison with uncontaminated samples.

Key topics and technical requirements

• Scope: Laboratory exposure of brake lining samples to detrimental environments and comparison versus uncontaminated controls.
• Test apparatus: Containers for fluids and immersed samples; a ball-ended micrometer (thickness to 0.01 mm tolerance); a material shear test rig per ISO 6311 or ISO 6312.
• Sampling & preparation: Take at random a minimum of 15 representative linings or pads of the same shape/size/material. Prepare specimens per ISO 6311 or ISO 6312. Mark five selected spots on each sample for thickness readings and identify each sample.
• Grouping: Samples are placed into five groups of three (Groups I–V) and stored vertically during contamination to maximize exposed surface without samples touching.
• Contamination regimes:
  • Group I: control (stored in normal atmosphere for 7 days).
  • Group II: water immersion for 7 days.
  • Group III: sodium chloride solution (100 g/L) immersion for 7 days.
  • Group IV: lubricating oil (ISO 1817 specification, oil no. 2) immersion for 48 hours.
  • Group V: brake fluid (ISO 4926 compatibility fluid) immersion for 48 hours.
• Measurements and tests: Measure thickness at five spots (average used) within 10 minutes after drying and immediately prior to shear testing. Conduct shear strength tests per ISO 6311 or ISO 6312.
• Evaluation:
  • Change in thickness = difference in average thickness before and after contamination.
  • Change in shear strength = difference between contaminated sample average and uncontaminated sample average; may be expressed as a percentage of the uncontaminated value.

Applications and practical value

• Validates brake lining and pad resistance to environmental contamination (rain, sea spray, axle oil leaks, wheel cylinder leaks).
• Supports quality control, product development and comparative performance testing for brake materials with organic content.
• Helps manufacturers, independent test labs and vehicle OEMs assess durability, safety margins and compliance of brake linings under realistic contamination scenarios.

Who should use this standard

• Brake lining and brake-pad manufacturers
• Automotive component test laboratories and QA departments
• Vehicle OEM engineers responsible for brake system performance
• Regulatory bodies and certification organizations evaluating braking safety

Related standards

• ISO 6311 - Internal shear strength of lining materials - Test procedure
• ISO 6312 - Shear strength of disc brake pad and drum brake shoe assemblies - Test procedure
• ISO 1817 - Vulcanized rubbers - Resistance to liquids - Method of test
• ISO 4926 - Hydraulic brake systems - Reference fluids / compatibility fluids
• ISO 611 - Braking terminology

Keywords: ISO 6314:1980, brake linings resistance, brake pad contamination testing, shear strength, thickness change, drum brake linings, disc brake pads.