Series 50 – Section 20.1 Obstruction or Damage to Rocker Cover Breather

Section 20.1
Obstruction or Damage to Rocker Cover Breather

To determine if an obstructed or damaged breather is causing excessive crankcase pressure, perform the following: ‪

1. Perform a crankcase pressure test; refer to "29.3 Crankcase Pressure Test (Governed Speed No Load)" .
   1. If the engine crankcase pressure is less than 3 in. H₂ O (0.75 kPa), check the air compressor; refer to "20.2 Defective Air Compressor" .
   2. If the engine crankcase pressure is greater than 3 in. H₂ O (0.75 kPa), replace wire mesh element; refer to "20.1.1 Rocker Cover Breather Resolution" .

Section 20.1.1
Rocker Cover Breather Resolution

Perform the following steps to replace wire mesh element replacement:‪

1. Remove the valve rocker cover(s); refer to "1.6.2 Cleaning and Removing of Two-piece Rocker Cover-Diesel Engines Only" .
2. Remove the wire mesh form the rocker cover; refer to "1.6.3 Disassembly of Two-piece Rocker Cover-Diesel Engines Only" .
3. Install a new wire mesh element to the rocker cover; refer to "1.6.6 Pre-installation of Rocker Cover Base" .
4. Install the rocker cover to the engine; refer to "1.6.7 Installation of the Two-piece Rocker Cover Base" .
5. Verify replacement of wire mesh element; refer to "20.1.1.1 Test Engine with New Wire Mesh Element" .

Section 20.1.1.1
Test Engine with New Wire Mesh Element

Perform the following steps to determine if the new wire mesh element resolved the excessive crankcase pressure:‪

1. Start and run the engine.
2. Perform a crankcase pressure test; refer to "29.3 Crankcase Pressure Test (Governed Speed No Load)" .
   1. If the engine crankcase pressure is less than 3 in. H₂ O (0.75 kPa), no further troubleshooting is required. Shut the engine down.
   2. If the engine crankcase pressure is greater than 3 in. H₂ O (0.75 kPa), check the air compressor; refer to "20.2 Defective Air Compressor" .