AL-KO 12.25" x 3.5" Electric Brake Assembly – 9K / 10K / 12K Axle – 5 Bolt – RSA – LEFT
AL-KO 12.25" x 3.5" electric brake assembly designed for 9,000 lb, 10,000 lb, and 12,000 lb trailer axle applications. This is the LEFT (driver side) configuration and mounts to a 5-bolt brake flange.
Brake assembly is fully pre-assembled on the backing plate and includes shoes, magnet, return springs, and RSA adjuster mechanism. Listing is for ONE complete brake assembly (one wheel).
R&P Knowledge Hub
12.25" x 3.5" electric brake assemblies are commonly used on heavy-duty 9K–12K axles found on equipment trailers, deckovers, and commercial haulers. These assemblies require a 5-bolt mounting flange and must be matched to the correct drum width.
RSA (Reverse Self-Adjusting) means the brake automatically maintains proper shoe-to-drum clearance during forward and reverse stops, reducing manual adjustment requirements. Verify drum size, flange bolt pattern, and correct side orientation before installation.
Features
- 12.25" diameter x 3.5" wide brake assembly
- 5-bolt mounting flange configuration
- RSA – Reverse Self-Adjusting mechanism
- Pre-assembled backing plate for direct replacement
- AL-KO heavy-duty electric drum brake system
Specifications
| Specification | Detail |
| Brake Type | Electric Drum |
| Brake Size | 12.25" x 3.5" |
| Axle Rating | 9,000 lb / 10,000 lb / 12,000 lb |
| Mounting Pattern | 5 Bolt Flange |
| Adjustment Type | Reverse Self-Adjusting (RSA) |
| Orientation | Left (Driver Side) |
Verify specifications before installation.
