The Midland Haldex KN26121 is a Trailer Brake Control (TBC) valve designed for service brake priority applications, identified by its black cover. The valve body is molded from engineering-grade composite (EGC), which resists corrosion and chemical exposure. Port sizing: 3/8 in. supply, 3/8 in. control, 1/2 in. reservoir, and four 3/8 in. delivery ports, all with push-to-connect (PTC) fittings. Integral anti-compounding and internal pressure protection isolate reservoir failures to prevent unintended spring brake application. An exhaust cover keeps road debris out, and inlet filters guard against system contamination. Cross-referenced as MDKN26121, HDX-KN26121, and N34031AA. Call us to confirm proper fit for your trailer brake system.
Features
Service Brake Priority configuration, identified by black cover (Spring Brake Priority models carry a white cover)
Engineering-grade composite (EGC) body resists corrosion and chemical exposure
Supply port: 3/8 in. | Control port: 3/8 in. | Reservoir port: 1/2 in. | Delivery ports (4): 3/8 in., all PTC fittings
Integral anti-compounding and internal pressure protection isolate reservoir failures
Exhaust cover blocks road dirt and grime from entering the valve
Inlet filters prevent system contamination and support long service life
Tech Specs
- Supply Port: 3/8 in.
- Control Port: 3/8 in.
- Reservoir Port: 1/2 in.
- Delivery Ports (4): 3/8 in.
- Fitting Type: Push-to-Connect (PTC)
- Priority Type: Service Brake Priority
- Cover Color (Service Brake Priority): Black
- Cover Color (Spring Brake Priority): White
- Cross References: MDKN26121, HDX-KN26121 or HDXKN26121, HDX KN26121, 5396-KN26121 or 5396KN26121, N34031AA
