Dexter 12-1/4" x 3-3/8" Electric Brake Assembly – 9K–10K Axle – Self-Adjusting – Left Hand
Genuine Dexter 12-1/4" x 3-3/8" electric trailer brake backing plate assembly designed for 9,000–10,000 lb trailer axle applications. This is the left-hand (driver side) configuration.
This brake assembly features a forward self-adjusting mechanism and comes fully pre-assembled on the backing plate for straightforward installation.
Listing is for ONE brake assembly (one wheel).
Features
- 12-1/4" diameter x 3-3/8" wide
- Designed for 9,000–10,000 lb axles (rated per pair)
- Electric drum brake operation
- Forward Self-Adjusting (FSA) feature
- 7-bolt mounting flange
- Left-hand (driver side) orientation
- Yellow wire magnet configuration
- Pre-assembled backing plate design
R&P Knowledge Hub
Electric brake assemblies operate through a brake controller that energizes the magnet inside the drum, expanding the brake shoes outward to create braking force.
The Forward Self-Adjusting (FSA) feature automatically maintains proper shoe-to-drum clearance as lining wear occurs. When enough gap develops, the adjuster mechanism advances the screw assembly at the bottom of the brake, expanding the shoes and maintaining consistent braking performance.
12-1/4" x 3-3/8" brake assemblies are commonly found on 9K–10K trailer axles. Always verify brake size, axle capacity, mounting pattern (7 bolt), and correct left/right orientation before ordering.
Specifications
| Specification | Detail |
| Manufacturer | Dexter |
| Brake Diameter | 12-1/4 Inches |
| Brake Width | 3-3/8 Inches |
| Axle Rating | 9,000–10,000 lbs (per pair) |
| Mounting Pattern | 7 Bolt Flange |
| Orientation | Left Hand (Driver Side) |
| Brake Type | Electric Drum Brake |
| Adjustment | Forward Self-Adjusting |
Verify specifications before installation.