Description
D-2 style air-brake compressor governor (PAI EM36450A) with an adjustable 100-120 psi cut-in / cut-out range and 200°F max operating temperature. Aftermarket replacement for the Bendix 275491 D-2 governor, Midland KN18530, and Mack 20QE275P1 — the unloader / governor on most Class 6-8 trucks running an engine-driven compressor with reservoir tanks.
Signs You Need a New Air Governor
- Compressor never unloads — system pressure climbs past 130 psi and pops the safety valve
- Compressor never cuts in — system pressure drops below 80 psi without the compressor restarting
- Constant compressor cycling at idle (governor float)
- Audible air leak from the governor exhaust port
- Excessive moisture or oil at the air-dryer / wet tank because the unloader never opens
Specifications
| Manufacturer | PAI Industries |
|---|---|
| Part Number | EM36450A |
| Part Type | D-2 Air Governor (Compressor Cut-Out) |
| Operating Range | 100-120 psi (adjustable) |
| Max Operating Temperature | 200°F |
| Style | D-2 Governor |
Cross References
This D-2 governor replaces or is equivalent to the following part numbers:
- Bendix: 275491
- Haldex / Midland: KN18530
- Mack: 20QE275P1
- Fortpro: F224710
Applications
Universal D-2 governor for heavy-duty trucks, tractors, and buses with engine-driven air compressors and 100-120 psi reservoir cut-out. Most commonly seen on Mack, International, and Class 8 fleet trucks; the D-2 design has been a standard service governor across the industry for decades.
Verify your existing governor is the D-2 style (round body, three NPT ports, spring adjustment under cap) before ordering. D-2 is the dominant style on most pre-2010 HD trucks; some late-model trucks use a different unloader design.
