Longer stroke brake chambers identification Over recent years longer stroke brake chambers have become standard on a range of truck models. These chambers are not always easily identifiable and they all have the same stroke. don’t A mismatch of chambers may lead to brake imbalance issue across an axle, particularly during a Roller Brake Testing. Refer to the applicable TAP for the detailed roller brake testing procedure. Component suppliers always recommend fitting matching chambers and other componentry. Warning Ensure components are identical across an axle and, optimally, within an axle group. Identify long stroke brake chambers by two of the following methods (Refer to SAE J1817 for details): Trapezoidal shaped tag with the stroke information detailed (figure 3) Square boss around the air supply port or ports (figure 4) chamber’s Embossed or cast-in service instruction advising chamber details (figure 5) Figure 3: Reference tag Figure 4: Boss shape Figure 5: Body marking Source: Haldex Haldex BPW Transpec Chamber stroke / readjustment lengths Long stroke brake chambers are available in 3 classes or bands, based on their increase in stroke from the standard rated brake chamber stroke. Class I Class II Class III 6.4 to 12.4 mm 12.7 to 18.8 mm 19 mm greater than standard An actuator having a stroke of rated stroke 0.25 to 0.50 to 0.49” 0.74” 0.75” Table 1: Long stroke actuator classes. Refer to SAE J1817 for details. Table 2 lists the SAE recommendation for both the stroke length and maximum adjustment limit for brake chambers. Long stroke Chamber brake chambers Type Standard stroke or brake chambers Class I Class II Class III size Std. + 0.25" (6.4 mm)* Std. + 0.50" (12.7 mm)* Std. + 0.75" (19.0 mm)*
Longer stroke brake chambers identification Over recent years longer stroke brake chambers have become standard on a range of truck models. These chambers are not always easily identifiable and they don’t all have the same stroke. A mismatch of chambers may lead to brake imbalance issue across an axle, particularly during a Roller Brake Testing. Refer to the applicable TAP for the detailed roller brake testing procedure. Component suppliers always recommend fitting matching chambers and other componentry. Warning Ensure components are identical across an axle and, optimally, within an axle group. Identify long stroke brake chambers by two of the following methods (Refer to SAE J1817 for details): Trapezoidal shaped tag with the stroke information detailed (figure 3) Square boss around the chamber’s air supply port or ports (figure 4) Embossed or cast-in service instruction advising chamber details (figure 5) Figure 3: Reference tag Figure 4: Boss shape Figure 5: Body marking Source: Haldex Haldex BPW Transpec Chamber stroke / readjustment lengths Long stroke brake chambers are available in 3 classes or bands, based on their increase in stroke from the standard rated brake chamber stroke. Class I Class II Class III An actuator having a stroke of 6.4 to 12.4 mm 12.7 to 18.8 mm 19 mm greater than standard rated stroke 0.25 to 0.49” 0.50 to 0.74” 0.75” Table 1: Long stroke actuator classes. Refer to SAE J1817 for details. Table 2 lists the SAE recommendation for both the stroke length and maximum adjustment limit for brake chambers. Chamber Type or size Standard stroke brake chambers Long stroke brake chambers Class I Std. + 0.25" (6.4 mm)* Class II Std. + 0.50" (12.7 mm)* Class III Std. + 0.75" (19.0 mm)*
TAPs%20-%20Slack%20adjuster%20setup%20and%20compliance%20to%20the%20NHVIM%20-%2030%20September%202016.docx