Usage:
D25C, D25D, D30C, D30D, D35C, D35HP, D40D, D44, D44B, D250B, D300B, D350C, D350D, D400, D440D, D550, D550B Trucks
Access is restricted to the test point in the 6U5704 Governor Valve, which is part of the air system. This can cause difficulty in connecting a pressure gauge to check governor settings. The governor valve inlet hose is more accessible and can be used as an alternative test point for connecting an air pressure gauge.
The exact location of the 6U5704 Governor Valve varies between models, ranges and types but the inlet line to the valve is accessible in each situation.
Refer to the Service Manual for details of the governor valve testing and adjusting procedures. If access to the recommended test port is difficult, install a swivel tee between the valve inlet port and the air supply line as a temporary connection point for the pressure gauge. On D250B and D300D Trucks, use a 520572 Swivel Tee (7/16" JIC). On all other trucks, use a 6S5693 Swivel Tee (3/4" JIC). These two swivel tees are included in the 4C4890 Pressure Gauge Kit.