Brake Chamber Size & Dimension Charts - Type 12 through Type 36
Complete dimension tables for BRC spring brake and service brake chambers. Includes outside diameter, mounting stud centers, push-rod thread, and approximate weight - verified to SAE J1469 compliance standards.
All BRC brake chamber dimensions adhere to SAE J1469 interchangeability standards - the same protocol used by Bendix, Haldex, Meritor, and Knorr-Bremse. Chambers that don't meet this standard can cause bracket fatigue, push-rod binding, and premature failure.
Spring Brake Chamber Dimensions (Type 20/24 to Type 30/30)
Accurate dimensions prevent installation failures on tandem axle setups. This chart covers double-diaphragm spring brake chambers (combination service + parking). Compare outside diameter (OD), mounting stud centers, push-rod thread, and approximate weight before ordering. All dimensions verified to SAE J1469.
| Type Size | Outside Diameter (OD) | Mounting Stud Centers | Pushrod Thread | Approx. Weight |
|---|---|---|---|---|
| Type 20/24 | 6.8" (173mm) | 4.75" (120.7mm) | 5/8-11 UNC | 16.5 lbs |
| Type 24/24 | 7.1" (180mm) | 4.75" (120.7mm) | 5/8-11 UNC | 17.2 lbs |
| Type 24/30 | 8.2" (208mm) | 4.75" (120.7mm) | 5/8-11 UNC | 19.8 lbs |
| Type 30/30 (Std) | 8.2" (208mm) | 4.75" (120.7mm) | 5/8-11 UNC | 20.5 lbs |
| Type 30/30 (LS) | 8.2" (208mm) | 4.75" (120.7mm) | 5/8-11 UNC | 21.1 lbs |
Important Note on Stroke Type
NOTE: Type 30/30 LS refers to Long Stroke. Confirm your existing chamber's stroke length before ordering - long-stroke chambers are not interchangeable with standard-stroke chambers on the same slack adjuster.
Service Brake Chamber Dimensions (Type 12 to Type 30)
Service brake chambers are single-diaphragm chambers used on steer axles, drive axles, trailer axles, and lift axle applications where a parking spring is not required. Compare outside diameter (OD), mounting stud centers, and push-rod thread before ordering.
| Type Size | Outside Diameter (OD) | Mounting Stud Centers | Pushrod Thread | Approx. Weight |
|---|---|---|---|---|
| Type 12 | 5.7" (145mm) | 4.75" (120.7mm) | 5/8-11 UNC | 8.8 lbs |
| Type 16 | 6.4" (162mm) | 4.75" (120.7mm) | 5/8-11 UNC | 10.6 lbs |
| Type 20 | 6.8" (173mm) | 4.75" (120.7mm) | 5/8-11 UNC | 12.4 lbs |
| Type 24 | 7.1" (180mm) | 4.75" (120.7mm) | 5/8-11 UNC | 14.1 lbs |
| Type 30 | 8.2" (208mm) | 4.75" (120.7mm) | 5/8-11 UNC | 16.8 lbs |
Brake Chamber Size & Dimension FAQs
Common questions from technicians and fleet managers about brake chamber dimensions.