SEAL-O-RING 3E6736 - Caterpillar

Diagnostic Codes
This procedure covers the following diagnostic trouble codes:
Table 1
Diagnostic Trouble Codes for High Crankcase Pressure    
J1939 Code    Description    Comments    
101-15     Engine Crankcase Pressure : High - Least Severe (1)     The Engine Control Module (ECM) activates this code when the crankcase pressure has exceeded the limit for a programmed period. The amber warning lamp is illuminated. The code is logged.
This code can be caused by an obstructed tube, an obstructed filter, or an obstructed hose.    
101-16     Engine Crankcase Pressure : High - Moderate Severity (2)     The ECM activates this code when the crankcase pressure has exceeded the limit for a programmed period. The amber warning lamp is illuminated. The code is logged. Engine power is derated by 100 percent.
This code can be caused by an obstructed tube, an obstructed filter, or an obstructed hose.    System Operation
Illustration 1 g01413562
Typical crankcase ventilation system (1) Crankcase pressure sensor (2) Breather (3) Crankcase ventilator filter (4) Filter housing (5) Oil drain tube (6) Fumes disposal tubeThe engine is equipped with an open crankcase ventilation system. Refer to Illustration 1. Differential pressure sensor (1) monitors the level of crankcase pressure. Breather (2) contains passages that route crankcase pressure and atmospheric pressure to the sensor. Filter (3) filters the blowby before venting the blowby through tube (6) . Oil is returned to the oil pan via tube (5) .Troubleshooting
Check the crankcase ventilation system for obstructions by performing the following procedure:
Inspect filter (3) . Discoloration of the filter is normal. The filter must be replaced according to the maintenance interval schedule that is indicated in the engines Operation and Maintenance Manual (OMM). Determine the engines operating hours. Interview the operator. Determine if the filter was replaced at the appropriate time. Replace the filter, if necessary. Be sure that the filter is torqued to the correct value during installation.Check for excessive emulsion at the top of the filter. Excessive emulsion is caused by the following conditions:Extended Idling - Idling the engine for long periods of time can cause excessive emulsion. Interview the operator. Determine if the engine has been allowed to idle for long periods of time. If so, excessive idling is the cause of the emulsion.Overcooling - Overcooling can cause excessive emulsion. Refer to Troubleshooting, "Coolant Temperature Is Low" for additional information.
Inspect fumes disposal tube (6) for obstructions.
Inspect the tube between breather (2) and filter housing (4) . Look for obstructions.
Check the differential pressure sensor.
Remove the differential pressure sensor from the breather. Inspect the ports on the bottom of the sensor. Check the ports for obstructions.
Verify that the two O-ring seals between the sensor and the breather are in good condition.
Illustration 2 g01413592
Passages in the breathers
Refer to Illustration 2. Verify that both of the passages in the breather are free of obstructions.