Usage:
992B Loaders;
773 and 777 Trucks;
772 and 776 Tractors;
641B, 651B, 657B Tractors;
D346 ( 98N ) and D348 ( 57K ) Vehicular Engines
The turbocharger lubrication valve for the above machines gives an immediate flow of unfiltered oil (oil that is not filtered) to the turbocharger bearings when the engine is first started. As the pressure of the filtered oil increases, the plunger will move against the force of the spring. The flow of unfiltered oil is stopped and only filtered oil then flows to the turbocharger bearings.
If the lubrication valve is removed from the engine for any reason, make sure it is assembled correctly at time of installation. The valve plunger must be installed first, then the spring and cover. See the illustration. If the valve is not assembled correctly, the flow of unfiltered oil will not be stopped. This can cause early failure of engine components.
Correct installation of valve plunger and spring.