QC/T 592-2025 Performance requirements and bench test methods for automobile hydraulic brake caliper assembly English, Anglais, Englisch, Inglés, えいご
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ICS
T
Professional Standard of the People's Republic of China
QC/T 592-2025
Replaces QC/T 592-2013
Performance requirements and bench test methods for automobile hydraulic brake caliper assembly
汽车液压制动钳总成性能要求及台架试验方法
(English Translation)
Issue date: 2025-12-17 Implementation date: 2026-07-01
Issued by the Ministry of Industry and Information Technology of the People's Republic of China
Contents
Foreword
1 Scope
2 Normative References
3 Terms and Definitions
4 Performance Requirements
4.1 Vacuum Tightness
4.2 Low-pressure Tightness
4.3 High-pressure Tightness
4.4 Bleeder Screw Tightness
4.5 Inlet Port Tightness
4.6 Required Fluid Amount
4.7 Drag Torque
4.8 Caliper Rigidity
4.9 Piston Retraction Amount
4.10 Piston Sliding Resistance
4.11 Piston Actuation Pressure
4.12 Caliper Sliding Resistance
4.13 Brake Pad Sliding Resistance
4.14 Strength
4.15 Durability
4.16 Water Resistance
4.17 Corrosion Resistance
5 Test-related Requirements
5.1 Test Equipment Requirements
5.2 Sample Requirements
6 Test Methods
6.1 Vacuum Tightness
6.2 Low-pressure Tightness
6.3 High-pressure Tightness
6.4 Bleeder Screw Tightness
6.5 Inlet Port Tightness
6.6 Required Fluid Amount
6.7 Drag Torque
6.8 Caliper Rigidity
6.9 Piston Retraction Amount
6.10 Piston Sliding Resistance
6.11 Piston Actuation Pressure
6.12 Caliper Sliding Resistance
6.13 Brake Pad Sliding Resistance
6.14 Strength
6.15 Durability
6.16 Water Resistance
6.17 Corrosion Resistance
Performance Requirements and Bench Test Methods for Automotive Hydraulic Brake Caliper Assemblies
1 Scope
This document specifies the performance requirements, test-related requirements, and describes bench test methods for hydraulic brake caliper assemblies (hereinafter referred to as “brake caliper assemblies”) used in automotive service brakes.
This document applies to hydraulic brake caliper assemblies used in service brakes for N-category vehicles as defined in GB/T 15089 and M-category vehicles with a maximum design total mass not exceeding 3500 kg. Other categories of hydraulic brake caliper assemblies may refer to this document for implementation.
2 Normative References
The contents of the following documents become essential provisions of this document through normative reference herein. For dated references, only the edition corresponding to that date applies. For undated references, the latest edition (including all amendments) applies.
GB/T 5620 Road Vehicles—Motor Vehicles and Trailers—Braking—Vocabulary
GB/T 10125 Corrosion Tests in Artificial Atmospheres—Salt Spray Tests
GB/T 15089 Classification of Power-driven Vehicles and Trailers
QC/T 316 Bench Test Methods for Fatigue Strength of Automotive Service Brakes
QC/T 564 Performance Requirements and Bench Test Methods for Passenger Car Service Brakes
3 Terms and Definitions
The terms and definitions defined in GB/T 5620 and the following apply to this document.
3.1 Required Fluid Amount
The amount of brake fluid required by the brake caliper assembly to establish a specified hydraulic pressure.
3.2 Drag Torque
The rotational torque exerted by the brake caliper assembly on the brake disc after brake release.
3.3 Full-wear Brake Pads
Brake pads where the friction material is worn down to a remaining thickness of 2 mm or when the wear indicator is triggered.
3.4 Half-wear Brake Pads
Brake pads where the thickness of the friction material is worn down to half of its original thickness.
3.5 Piston Sliding Resistance
The resistance to movement of the piston in the retraction direction.
3.6 Caliper Sliding Resistance
The resistance to movement of the caliper body of a floating brake caliper assembly on the guide pins.
3.7 Brake Pad Sliding Resistance
The resistance to movement of the brake pad within the guide rods or guide grooves.
4 Performance Requirements
4.1 Vacuum Tightness
For brake caliper assemblies used in vehicles employing vacuum filling, when tested according to 6.1, the pressure increase shall not exceed 0.2 kPa.
4.2 Low-pressure Tightness
When tested according to 6.2, the pressure drop shall not exceed 3 kPa.
4.3 High-pressure Tightness
When tested according to 6.3, the pressure drop shall not exceed 0.2 MPa.
4.4 Bleeder Screw Tightness
When tested according to 6.4, there shall be no brake fluid leakage at the bleeder screw.
4.5 Inlet Port Tightness
When tested according to 6.5, there shall be no brake fluid leakage at the bolt connections.
4.6 Required Fluid Amount
When tested according to 6.6, the required fluid amount shall meet the requirements specified in the product technical documentation.
4.7 Drag Torque
When tested according to 6.7, the drag torque during the first revolution of the brake disc shall not exceed 3.5 N·m, and the drag torque during the tenth revolution shall not exceed 2 N·m, or it shall meet the requirements specified in the product technical documentation.
4.8 Caliper Rigidity
When tested according to 6.8, the deformation of the caliper body along the axis of the hydraulic cylinder shall meet the requirements specified in Table 1 or the product technical documentation.
Table 1 Performance Requirements for Caliper Rigidity
4.9 Piston Retraction Amount
When tested according to 6.9, the piston retraction amount for floating brake caliper assemblies shall not exceed 0.6 mm, and the single-side piston retraction amount for fixed brake caliper assemblies shall not exceed 0.3 mm, or it shall meet the requirements specified in the product technical documentation.
4.10 Piston Sliding Resistance
When tested according to 6.10, the sliding resistance for a single piston shall be within the range of 98 N to 700 N, or it shall meet the requirements specified in the product technical documentation.
4.11 Piston Actuation Pressure
When tested according to 6.11, the input hydraulic pressure at which the piston begins to move shall not exceed 0.1 MPa, or it shall meet the requirements specified in the product technical documentation.
4.12 Caliper Sliding Resistance
When tested according to 6.12, the caliper sliding resistance for floating brake caliper assemblies shall not exceed 100 N, or it shall meet the requirements specified in the product technical documentation.
4.13 Brake Pad Sliding Resistance
When tested according to 6.13, the sliding resistance of the brake pads shall meet the requirements specified in the product technical documentation.
