Description
PAI 645052 fuel return-line check valve for Detroit Diesel Series 60 12.7L and 14L engines. The one-way valve installs on the cylinder head fuel return passage and holds fuel in the head when the engine is shut off, preventing drain-back to the tank and the long crank/rough first-minute symptom that follows. Direct replacement for Detroit OEM 23516918.
Signs You Need a New Fuel Check Valve
- Hard starting or extended cranking after the truck sits overnight
- Engine misfires or runs rough for the first minute after start
- Fuel filter bowl drains down when the engine is shut off
- Loss of prime requiring multiple cranking cycles to start
Specifications
| Manufacturer | PAI Industries |
|---|---|
| Part Number | 645052 |
| Part Type | Fuel Return-Line Check Valve |
| Engine Compatibility | Detroit Diesel Series 60 12.7L, 14L |
| Orifice / Body | 0.200″ ID, 0.87″ hex, 2.40″ length |
| Thread | 3/8″ female × 3/4-16 male |
| Warranty | 2-year unlimited mileage (PAI) |
Cross References
This check valve replaces or is equivalent to the following part numbers:
- Detroit Diesel: 23516918
Applications
This check valve fits the following engines:
- Detroit Diesel Series 60 12.7L (1996-2007)
- Detroit Diesel Series 60 14L (1999-2007)
Representative vehicles using these engines:
- Freightliner Classic XL, Columbia, Century Class (1996-2007)
- Western Star 4900, 5900 (1996-2007)
- Sterling AT9500, A-Line (2001-2007)
Companion check valves for the same fuel rail: PAI 645050 (replaces Detroit 23516993) and PAI 645051 (replaces Detroit 23516919).
Verify your engine serial number and rail configuration before ordering. The Series 60 fuel rail uses three different check valves with similar appearance — confirm which port you are servicing.
