Replaced and Ready: Hose Assembly Failure Service

posted on Friday, December 8, 2023 in Dealer News

Hose assembly failures can cause serious damage and lead to costly downtime. While failures are a part of business, knowing what causes them and implementing a preventative maintenance schedule can help you prepare to minimize downtime.

As you’re performing your routine inspections, there are several common factors to check:

1. Abrasion: Excessive rubbing of the hose against an external object or even another hose can wear away the cover and eventually the reinforcement layers. If the cover appears damaged, that’s a sign that failure is imminent.
2. Minimum bend radius: Hose assemblies can fail relatively quickly if the minimum bend radius is exceeded. For high-pressure applications, premature failure could occur due to increased stress on the hose. In vacuum or suction applications, if the bend radius is exceeded, the hose may tend to be flat in the bend area. This will hinder or restrict flow – possibly even causing the hose to kink.
3. Heat aged: Overheating, from the internal hydraulic oil temperature or the external ambient temperature, will cause the hose to become very stiff. The inner tube will harden and begin to crack because the plasticizers in the elastomer will break down or harden under high temperatures. In some cases, the cover may show signs of being dried out.
4. Improper assembly: Contamination can be a result of poor assembly practices and can cause several problems for a hydraulic hose assembly. When cutting a hose, metal particles and debris can settle inside the hose if not properly flushed. This abrasive debris left in the hose will contaminate the hydraulic system, potentially causing small fractures to develop, resulting in leakage.
5. Fluid compatibility: Incompatible fluids will cause the inner tube of the hose assembly to deteriorate, swell and delaminate. In some cases, the inner tube can also partially wash. Verify that the fluid is not only compatible with the inner tube, but also the outer cover, fittings and even O-rings.
6. Insertion depth: Fittings need to be pushed on completely to meet the recommended insertion depth. If the hose insertion depth is not met, fittings can blow off, leaving a failed hose assembly. The last grip in the fitting shell is essential to the holding strength.
7. Dry/aged air: To avoid dry or aged air problems, confirm your hose is rated for extremely dry air. Hoses with inner tubes of PKR or EPDM rubber are preferred for these applications.
8. Tube erosion: Tube erosion is usually caused by a concentrated high-velocity stream of fluid or by small particles in the fluid. A hose assembly that is bent too tight for flow or an over abrasive medium for the inner tube can also lead to erosion.

At Martin Equipment, it’s our job – and pleasure – to keep your equipment up and running. If you have any questions regarding hose repair and replacements or would like a free consultation, please contact us.