Small Leak in Hydraulic Hose Reveals Big Problem

Abstract

A leaking rubber hydraulic hose was investigated as it represented one of several failures that occurred over a relatively short period of time. Fluid appeared to be leaking from a pinhole size tear in the outer jacket of the hose. However, this was only minor damage relative to the extensive cracking that was discovered on the inside layer of the hose. The failure analysis included visual, microscopic, and scanning electron microscopic (SEM) examinations of the failed part. In addition, the material used to fabricate the hose was characterized using Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). It was concluded that the inner hose material was contaminated with another type of rubber, and had fractured due to poor mechanical integrity. The personnel responsible for the manufacturing of the hose did not properly purge an older production run from the hose extruder.