1、SURFACE VEHICLE RECOMMENDED PRACTICE J1476 NOV2014 Issued 1987-06 Reaffirmed 2014-11 Superseding J1476 OCT2008 Parking Brake Structural Integrity Test Procedure Vehicles Over 4500 kg (10 000 lb) GVWRTruck and Bus RATIONALE J1476 has been reaffirmed to comply with the SAE five-year review policy. _ S
2、AE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefro
3、m, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2014 SAE International All rights reserved. No part of this publ
4、ication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-4970 (
5、outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/J1476_201411 1. SCOPE This SAE Recommended Practice establishes a method of evaluati
6、ng the structural integrity of the parking brake system of all new trucks, buses, and combination vehicles designed for roadway use in the following classifications: TRACTOR, TRAILER, TRUCK, AND BUS: over 4500 kg (10 000 lb) GVWR. 1.1 Purpose The main purpose of the document is to evaluate the struc
7、tural integrity of a vehicles parking brake system. However, other areas, such as suspension and drivetrain system, may also be evaluated during the test, provided that the criteria and procedure detailed as follows are not modified in any way. 1.2 Types of Parking Brake Systems to be Evaluated 1.2.
8、1 Manually AppliedMechanically Held 1.2.2 Power ReleasedMechanically Held 1.2.3 Power AppliedMechanically Held 2. REFERENCES 2.1 Applicable Publications The following publications form a part of this specification to the extent specified herein. Unless otherwise indicated, the latest version of SAE
9、publications shall apply. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. SAE J293 Truck and Bus Grade Parking Performance Requirements SAE J360 Truck and
10、 Bus Grade Parking Performance Test Procedure SAE J1729 Parking Brake Drawbar Pull Test ProcedureTruck and Bus SAE J2115 Air Brake Performance and Wear Test Code Commercial Vehicle Inertia Dynamometer SAE J2503 Drawbar Pull Performance Criteria 3. EQUIPMENT (WHERE APPLICABLE) 3.1 Brake apply device
11、(optional, but recommended to reduce variations in apply efforts) 3.2 Air pressure gages 3.3 Hydraulic pressure gages 3.4 Tire pressure gage 3.5 Torque wrench 3.6 Direct reading brake lining temperature instrument 3.7 Parking brake apply force transducer 3.8 Recording or readout device for transduce
12、rs 3.9 Heavy-duty winch or powered vehicle to pull test vehicle 3.10 Calibrated load cell 0 to 88 964 N (0 to 20 000 lb) 3.11 Suitable hook-up method for pulling test vehicle 3.12 Dolly for trailer testing 3.13 Trailer air-brake charging system 3.14 Wheel alignment equipment 4. TEST PREPARATION (WHE
13、RE APPLICABLE) 4.1 Calibrate instrumentation as required. 4.2 Install new brake lining, drums and/or rotors, and brake assemblies to the manufacturers specifications, except all brake fasteners applied to all components affected by reactive forces shall be at minimum specified torque. Record all tor
14、que values. Record pertinent brake parameters and specifications. Mark or scribe all mating surfaces for checking relative movement. 4.3 Install and locate thermocouples per SAE J2115 (where appropriate, one per brake). SAE INTERNATIONAL J1476 Reaffirmed NOV2014 Page 2 of 5_ 4.4 Adjust entire brake
15、system per the vehicle manufacturers specification. 4.5 Check wheel geometry of all applicable axles and adjust to manufacturers mean specification and record. 4.6 Install the tires and wheels offered by the manufacturer, which produce the largest tire rolling radius. Tires, at minimum, shall have a
16、 typical 200-mile preconditioning break-in and/or per the tire manufacture recommended break-in procedure, but not more than 20% worn. Set tire pressure per manufacturers specification for vehicle test weight specified in this document. 4.7 For those vehicles, which are equipped with power-assist br
17、ake actuation, the reservoir pressure shall be set at the vehicle manufacturers maximum recommended cutout pressure. 4.8 Actuation system to be installed, lubricated, adjusted, and inspected in accordance with the vehicle manufacturers specification. 4.9 For trailer testing with a winch, use an axle
18、 dolly. 4.10 The test vehicle shall be loaded to the manufacturers gross vehicle weight rating (GVWR) proportionally distributed according to individual axle system GAWRs. GVWR includes weight of test equipment and supporting dolly, if required. 5. TEST NOTES 5.1 If the parking brake is not used for
19、 service braking, burnish per SAE J360. 5.2 Adjust parking brake(s) and actuation systems in accordance with vehicle manufacturers specifications, before and after burnishing. 5.3 All tests are to be conducted on a Test Grade to the vehicle classification and application forces per SAE J293, or by a
20、n equivalent Drawbar Pull Test per SAE J2503 using a towing vehicle or a winch. Parking brake control systems that use energy from sources other than manual are excluded from the application force requirements. 5.4 Conduct the test on a dry, brushed Portland cement concrete surface (or other surface
21、 of equivalent coefficient of surface friction) that is free from loose materials. 5.5 Initial brake lining temperatures are not to exceed 66 C (150 F). 5.6 Combination vehicles shall be tested per SAE J360. 5.7 Data sheets shall provide for recording the following data: loaded weight, percent grade
22、 or drawbar pull force, identification of brake system, direction of test vehicle on the grade, lining temperature, applied force and/or pressure to parking brake system, and observation of wheel roll or lock and hold or slide. 6. METHOD OF CONDUCTING ON-GRADE TEST PER SAE J360 6.1 Drive the test ve
23、hicle up the test grade, stop, and hold with the service brakes until parking brake system is activated. For test grade, see 5.3. The service brake is not used in the following sequence, except as noted. 6.2 With vehicle declutched or transmission in neutral, follow appropriate procedure notes in 6.
24、2.1 through 6.2.3; when brake is applied, note any wheel slide or creep for a 5-min period, excluding air brakes. 6.2.1 Manually AppliedMechanically Held Apply brake level force, per 6.1 and 6.2, measured with force transducer to hold the test vehicle on the test grade. Record force on brake lever t
25、o hold vehicle parked with any force less than forces referenced in 5.3. Release brake lever and reapply to the same force at first vehicle movement. Repeat sequence for subsequent stops to 6.4 and 6.5. SAE INTERNATIONAL J1476 Reaffirmed NOV2014 Page 3 of 5_ 6.2.2 Power ReleasedMechanically Held (Fo
26、r example, Air “Off“, Spring “On“) Park test vehicle on test grade by applying parking brake with control valve. Allow time for pressure to build up to the maximum brake system pressure. Record pressure. Release parking brake with control valve. At first vehicle movement, reapply parking brake contr
27、ol valve. Repeat sequence for subsequent stops to 6.4 and 6.5. 6.2.3 Power AppliedMechanically Held Parking Brakes Park test vehicle on test grade by applying parking brake with brake lever or control valve. Release power apply to ensure the vehicle is held by mechanical means. Allow time for apply
28、power recovery pressure to build up to the manufacturers maximum brake system specification. Record pressure. Release parking brake according to manufacturers recommended procedure. At first vehicle movement, reapply parking brake with lever control or valve. Repeat sequence for subsequent stops to
29、6.4 and 6.5. 6.3 To test a trailers parking brake system when independent from the towing equipment, the trailer and dolly, if used, shall be positioned on the test grade by the towing equipment. Apply the trailers parking brake system following appropriate procedure in 6.2. Disconnect trailer from
30、towing equipment. Release dolly brakes where used; note any wheel slide or creep. NOTE: SUITABLE PRECAUTIONS MUST BE TAKEN TO STOP TRAILER IN CASE OF BREAKAWAY ON TEST GRADE. 6.4 Repeat 6.2 or 6.3 procedure for ten applications. Manually applied, mechanical parking brakes to have three additional ap
31、plications at 845 N (190 lb 10 lb) foot pedal or 600 N (135 lb 10 lb) hand lever without system readjustment. Power applied, mechanically held parking brakes to have three additional applications with power assist at maximum brake system pressure. Power released, mechanically held parking brakes to
32、have three additional applications while maximum brake system pressure is applied to the service brake actuators. 6.5 Vehicle to be turned around. Paragraphs 6.2 or 6.3, and 6.4 repeated on test grade in opposite direction. 7. METHOD OF CONDUCTING TEST ON ZERO GRADE (DRAWBAR TEST) PER SAE J1729 7.1
33、Position the vehicle attached to its towing vehicle or winch on a level surface. Note 5.3 for grade holding requirements. Pull test at zero grades to be equivalent. 7.2 With vehicle declutched or transmission in neutral, apply parking brakes as shown in 6.2. Pull the test vehicle with winch or towin
34、g vehicle to apply required load. Note any wheel slide or creep. 7.3 To test a trailer parking brake system when independent from the towing equipment, the trailer shall be positioned on test surface. An axle dolly with its brakes released shall be used to support the front end for trailer testing.
35、Apply brakes (see 6.2). Pull with towing vehicle or winch to apply required load. Record pull test at first vehicle movement. Note any wheel slide or creep. 7.4 Repeat sequence as specified in 6.4. 7.5 Vehicle to be tested with towing vehicle or winch pulling from opposite end and 7.1, 7.2, 7.3, and
36、 7.4 repeated. 7.6 In all cases, the drawbar pull force is the peak static breakaway value at the moment vehicle movement begins. 8. INSPECTION 8.1 Check and record wheel geometry of all applicable axles (see 4.5). 8.2 Check and record torque of all brake fasteners (see 4.2). 8.3 Inspect all compone
37、nts of the parking brake system for functional distortion, damage or relative movement. SAE INTERNATIONAL J1476 Reaffirmed NOV2014 Page 4 of 5_ 9. ACCEPTANCE REQUIREMENTS 9.1 When the brakes are released after test completion and the vehicle is moved, all wheels should rotate freely. 9.2 Wheel geome
38、try and axle alignment must be within manufacturers specifications. 9.3 After tests, parking brake system shall meet SAE J293 and/or SAE J2503 requirements depending on test method. 9.4 All brake fastener post test torques shall meet the manufacturers recommended specifications. 9.5 There shall be n
39、o permanent distortion of parking brake components, drum/rotors, or their attachment hardware or relative movement between the park brake assembly and the mating flange so as to prevent continued parking operation. 10. NOTES 10.1 Marginal Indicia A change bar (I) located in the left margin is for th
40、e 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. PREPARED BY THE SAE TRUCK AND BUS FOUNDATION BRAKE SUBCOMMITTEE OF THE SAE TRUCK AND BUS BRAKE COMMITTEE SAE INTERNATIONAL J1476 Reaffirmed NOV2014 Page 5 of 5_
