Usage:
D379, D398, D399 Industrial, Marine and Generator Set Engines;
G379, G398, G399 Natural Gas Engines
A differential pressure indicator (gauge) is available to monitor the oil pressure differential in the oil filter housing on the above engines. As the oil flows through the filters, debris is trapped in the filters and the oil pressure drop across the filters increases. This pressure drop can be monitored by a differential pressure indicator. When the pressure drop is 100 kPa (15 psi) or more, with the engine at operating temperature and speed, the oil filters should be changed.
Modifications can be made to the oil filter groups on the above engines so that the differential oil pressure between the unfiltered oil and the filtered oil can be checked. Use the procedure that follows to make the necessary modifications.
1. Put a red mark on the face of a 4W508 Differential Pressure Indicator (Gauge) at the 100 kPa (15 psi) position. See Illustration 1.
2. Install the indicator (gauge) in an unused opening of the gauge panel.
Illustration 1. Location of red mark on 4W508 Differential Pressure Indicator.
3. Remove the 3J5389 Plug (1/2 - 14 NPTF) from the cover. See Illustration 2. The higher, unfiltered oil pressure can be measured at the port where the plug was removed.
4. Connect an oil line from this port to the high pressure port of the 4W508 Differential Pressure Indicator.
5. Remove the 5M6214 Plug (1/8 - 27 NPTF) from the housing. See Illustration 2. The lower, filtered oil pressure can be measured at the port where this plug was removed.
6. Connect an oil line from this port to the low pressure port of the 4W508 Differential Pressure Indicator.
Illustration 2. Location of plugs in oil filter group.