SAE J2932:2017 pdf free
SAE J2932:2017 pdf free.Air Disc Brake Actuator Test Requirements
Hold-off pressure (pressure decreasing) is typically measured at 5 mm (0. 20 inch) stroke of the parking chamber from the actuator zero stroke position. A maximum target hold-off pressure of 483 kPa (70 psig) will in most applications,ensure the brakes do not drag. This requirement may vary depending on a vehicle air brake system, which may allow higher hold-off pressure or require lower hold-off pressure. A low hold-off pressure is preferred to ensure brakes do not drag.
Parking force output for the most common diaphragm actuated air disc brake parking chambers are given in Table 2 for reference purposes only. Force values given are nominal +1 0%. Various application differences may require other spring forces by size (type). Parking chamber force output is measured for a new complete combination actuator assembly after the power spring has been fully caged for 24 hours. Test procedures other than SAE J2902 may require the spring to be caged for a longer period. The forces given in Table 2 are only applicable to the test procedure in SAE J2902.
The service chamber diaphragm shall return to within 6.4 mm (0.25 inch) of zero stroke position within 60 seconds without assistance.
Brtle failure check: Upon disassembly (after completion of Section 18 Vibration Test, Test Unit A) there shall be no evidence of cracking or brittle failure of the diaphragm or the caliper flange seal boot.
A change bar (l) located in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only.SAE J2932 pdf free.
