Hydraulic brake hoses are critical components in any vehicle’s braking system, and their reliability is paramount for safety. To guarantee performance and durability, manufacturers like Nap Car Parts subject their brake hoses to a series of rigorous tests that meet and often exceed industry standards. These tests ensure that every NAP car part brake hose can withstand the extreme conditions and stresses of everyday driving, providing drivers with confidence in their vehicle’s braking system. Let’s delve into the specific tests that NAP car parts brake hoses undergo.
Torque Stripes: Preventing Installation Errors
Hydraulic brake hoses from NAP car parts are marked with distinct torque stripes. These are not merely cosmetic; they serve a vital purpose during installation. Each hose features at least two clear stripes, each a minimum of 1/16 inch wide, positioned on opposite sides and running parallel to the hose’s length. These stripes, sometimes interrupted by printed information about the hose specifications, act as visual guides to prevent twisting during assembly and installation. Ensuring the hose is installed without twists is crucial for maintaining proper brake fluid flow and preventing premature wear or failure.
Burst Pressure Testing: Withstanding Extreme Pressure
The integrity of a brake hose under pressure is non-negotiable. NAP car parts brake hoses are rigorously tested to ensure they can handle extreme hydraulic pressure without failing. Each hose assembly must withstand a water pressure of 4,000 psi for a full two minutes without rupturing. For hoses with a smaller diameter of 1/8 inch (3mm) or less, this requirement is even more stringent, withstanding pressures up to 7,000 psi. This burst pressure testing guarantees that NAP car parts brake hoses can confidently manage the high pressures generated within braking systems, even under hard braking or emergency situations.
Whip Testing: Endurance Under Constant Flexing
Brake hoses are subjected to constant movement and flexing as the vehicle operates. To simulate these conditions and assess long-term durability, NAP car parts employs whip testing. In this test, brake hoses are continuously bent on a flexing machine for an extended period of 35 hours while under pressure. This demanding test ensures that the hoses can endure the repetitive stress of flexing without cracking or failing, contributing to the longevity and reliability expected from NAP car parts.
Tensile Strength Testing: Resistance to Pulling Forces
Brake hoses must remain securely connected to their end fittings under significant pulling forces. NAP car parts brake hoses undergo tensile strength testing to validate this crucial aspect. In a slow pull test, the hose assembly must withstand a force of 325 pounds without the hose separating from its end fittings. Furthermore, in a fast pull test, simulating sudden stress, the requirement increases to 370 pounds. These tensile strength tests confirm the robust construction and secure fittings of NAP car parts brake hoses, ensuring they remain intact under stress.
Cold Resistance: Performance in Freezing Temperatures
Extreme cold can compromise the flexibility and integrity of some materials. To ensure reliable performance in all climates, NAP car parts brake hoses are subjected to cold resistance testing. A brake hose is chilled to below -49°F (-45°C) for 70 hours. After this extreme cold soak, the hose must not exhibit any visible cracks (without magnification) when bent around a cylinder. This cold resistance test guarantees that NAP car parts brake hoses remain flexible and functional even in the harshest winter conditions, maintaining consistent braking performance.
Chemical Resistance: Compatibility with Brake Fluid
Brake fluid is a harsh chemical, and brake hoses must be resistant to its corrosive effects to prevent degradation and failure over time. NAP car parts brake hoses are tested for chemical resistance by being exposed to a temperature of 248°F (120°C) for 70 hours while filled with SAE ‘Compatibility Fluid’. Following this rigorous chemical exposure, the hose must still pass a 4,000 psi burst test. This chemical resistance testing assures compatibility with standard brake fluids and confirms the hose material’s resilience to chemical breakdown, ensuring long-term reliability.
Ozone Resistance: Protection Against Environmental Degradation
Ozone is a naturally occurring gas that can degrade rubber and other materials over time. To ensure longevity and resistance to environmental factors, NAP car parts brake hoses undergo ozone resistance testing. A brake hose assembly is exposed to ozone for 70 hours at 104°F (40°C). Any cracks observed at a specified magnification level would constitute a failure. This ozone resistance test verifies that NAP car parts brake hoses are formulated to withstand environmental ozone exposure, preventing premature aging and cracking.
Fitting Corrosion Resistance: Durability Against Salt and Moisture
The end fittings of brake hoses are often exposed to moisture and road salt, which can lead to corrosion and weaken the connection. NAP car parts brake hose end fittings are tested for corrosion resistance by undergoing 24 hours of exposure to salt spray. After this exposure, the end fitting must show no base metal corrosion on the surface, except in areas where crimping or labeling has displaced the protective coating. This fitting corrosion resistance test confirms the durability of the fittings in harsh environments, ensuring a secure and long-lasting connection within the braking system.
Through these comprehensive and stringent testing procedures, NAP car parts ensures that their brake hoses meet the highest standards of quality, durability, and safety. Motorists can rely on NAP car parts for brake hoses that are built to last and perform reliably under all conditions.
