- Caterpillar Products: 3500C Engines
- Engine:Commercial 3500 and 3500B Family All
Introduction
Do not perform any procedure in this Special Instruction until you read this information and you understand this information.
In a crankcase ventilation system, the fumes from the crankcase are filtered before the fumes are sent to the air intake system. Steps must be taken in order to prevent oil from collecting on the components of the air intake system. Otherwise, the following problems can result:
- Decreased service life of air cleaner filters
- Premature plugging of the aftercooler core
Recommendations
Route the fumes from the crankcase through a commercially available aftermarket fumes disposal system. Direct the filtered fumes to the dirty side of the air cleaner filter elements.
Install soot filters on the air cleaner filter elements.
Monitor the differential pressure of the air intake system in order to determine when the system requires servicing.
Soot Filters
Soot filters fit firmly around 490 mm (19.3 inch) filter elements. Table 1 lists the part number and the height of the soot filters.
Soot Filters     | |
---|---|
Part Number of the Soot Filter     | Height of the Soot Filter     |
8N-2555     | 250 mm (10 inch)     |
115-3634     | 350 mm (14 inch)     |
115-3635     | 450 mm (18 inch)     |
The soot filter can be cleaned in order to remove oil. Wash the filter in a solution of soap and water. Allow the filter to dry completely before installing the filter.
Monitoring the Differential Pressure
A differential pressure gauge can be installed across the air side of the aftercooler core. The differential pressure provides an indication of the amount of plugging in the aftercooler core. The 152-2067 Oil Filter Pressure Differential Gauge Gp is suitable for monitoring the differential pressure. Table 2 lists the components and the locations for connecting the differential pressure gauge.
Components and Locations for Sensing the Differential Pressure     | |||
Type of Air Intake System     | Hose     | Fittings     | Location for the Fittings     |
Mechanical Unit Injection (MUI) Rear Turbocharger     |
5P-1519 Hose and internal 37 degree flare fitting ends     | 5J-7303 Elbow 8B-2664 Reducer Bushing 001-9440 Connector     |
Refer to Illustration 1 and Illustration 2     |
MUI Top Turbocharger     |
5J-7303 Elbow 8B-2664 Reducer Bushing 001-9440 Connector |
Refer to Illustration 3 and Illustration 4     | |
Electronic Unit Injection (EUI) Rear Turbocharger     |
001-9440 Connector (1) | Refer to Illustration 4     | |
EUI Top Turbocharger     |
001-9440 Connector (1) | Refer to Illustration 5     |
( 1 ) | Two Connectors are required |
Illustration 1 | g01446694 |
Typical configuration (1) Location for the 5J-7303 Elbow for the high pressure port |
Illustration 2 | g01446714 |
Port on a cylinder block (2) Location for the 8B-2664 Reducer Bushing and 001-9440 Connector for the low pressure port |
Illustration 3 | g01446657 |
Typical configuration (3) Location for the 5J-7303 Elbow for the high pressure port |
Illustration 4 | g01446721 |
Typical configuration (4) Location for the 001-9440 Connector for the low pressure port (5) Location for the 001-9440 Connector for the high pressure port |
Illustration 5 | g01446991 |
Typical configuration (6) Location for the 001-9440 Connector for the high pressure port (7) Location for the 001-9440 Connector for the low pressure port |
Table 3 provides the maximum allowable differential pressure across various components. Perform the appropriate service procedure if the differential pressure exceeds the value that is listed.
Maximum Differential Pressure and Service Procedures     | ||
---|---|---|
Component     | Maximum Differential Pressure     | Service Procedure     |
Aftercooler Core     | 7.5 kPa (30 inches of H2O)     |
Clean the aftercooler core.     |
Air Cleaner Filter     | 6.2 kPa (25 inches of H2O)     |
Clean the soot filter. Replace the air cleaner filter, if necessary.     |
Crankcase     | The crankcase pressure must be within 0.5 kPa (2 inch of H2O) of the barometric pressure.     |
Service the crankcase ventilator filter. Service the crankcase ventilation system, if necessary.     |