0439981 JOHNSON GEARCASE ASSY., Complete

Measuring Engine Oil Pressure
Work carefully around an engine that is running. Engine parts that are hot, or parts that are moving, can cause personal injury.
Keep all parts clean from contaminants.Contaminants may cause rapid wear and shortened component life.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat products.Dispose of all fluids according to local regulations and mandates.
Table 1
Required Tools
Tool Part Number Part Name Quantity
A 1U-5470
or
198-4240 Engine Pressure Group
or
Digital Pressure Indicator 1
Illustration 1 g00296486
1U-5470 Engine Pressure Group
Tool (A) measures the oil pressure in the system. This engine tool group can read the oil pressure inside the oil manifold.Note: Refer to Special Instruction, SEHS8907, "Using the 1U-5470 Engine Pressure Group" for more information. Refer to Operating Manual, NEHS0818, "Using the 198-4240 Digital Pressure Indicator" for more information.
Illustration 2 g00977330
Oil gallery plug
(1) Plug
Install Tool (A) into oil gallery plug (1). Note: Engine oil pressure to the camshaft and main bearings should be checked on each side of the cylinder block at oil gallery plug (1).
Start the engine. Run the engine with SAE 15W40 oil. Refer to Operation and Maintenance Manual, "Refill Capacities and Recommendations" for the recommendations of engine oil.
Record the value of the engine oil pressure when the engine is at operating temperature 100 °C (212 °F). The minimum engine oil pressure at 1800 rpm should be approximately 275 to 414 kPa (40 to 59 psi). Minimum engine oil pressure at low idle rpm (600 to 800 rpm) should be approximately 68 kPa (10 psi).
Compare the recorded engine oil pressure with the oil pressure indicators on the instrument panel and the engine oil pressure that is displayed on the electronic service tool.
An engine oil pressure indicator that has a defect or an engine oil pressure sensor that has a defect can give a false indication of a low oil pressure or a high oil pressure. If there is a notable difference between the engine oil pressure readings make necessary repairs.
If low engine oil pressure is determined, refer to "Reasons for Low Engine Oil Pressure".
If high engine oil pressure is determined, refer to "Reason for High Engine Oil Pressure". Reasons for Low Engine Oil Pressure
Keep all parts clean from contaminants.Contaminants may cause rapid wear and shortened component life.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat products.Dispose of all fluids according to local regulations and mandates.
Engine oil level is low. Refer to Step 1.
Engine oil is contaminated. Refer to Step 2.
The engine oil bypass valves are open. Refer to Step 3.
The engine lubrication system is open. Refer to Step 4.
The oil pickup tube has a leak or a restricted inlet screen. Refer to Step 5.
The engine oil pump is faulty. Refer to Step 6.
Engine Bearings have excessive clearance. Refer to Step 7.
Check the engine oil level in the crankcase. The oil level can possibly be too far below the oil pump supply tube. This will cause the oil pump not to have the ability to supply enough lubrication to the engine components. If the engine oil level is low add engine oil in order to obtain the correct engine oil level. Refer to Operation and Maintenance Manual, "Engine Oil" for the recommendations of engine oil.
Engine oil that is contaminated with fuel or coolant will cause low engine oil pressure. High engine oil level in the crankcase can be an indication of contamination. Determine the reason for contamination of the engine oil and make the necessary repairs. Replace the engine oil with the approved grade of engine oil. Refer to Operation and Maintenance Manual, "Engine Oil" for the recommendations of engine oil.
Caterpillar oil filters are built to Caterpillar specifications. Use of an oil filter not recommended by Caterpillar could result in severe engine damage to the engine bearings, crankshaft, etc., as a result of the larger waste particles from unfiltered oil entering the engine lubricating system. Only use oil filters recommended by Caterpillar.
If the engine oil bypass valves are held in the open position, a reduction in the oil pressure can be the result. This may be due to debris in the engine oil. If the engine oil bypass valves are stuck in the open position, remove each engine oil bypass valve and clean each bypass valve in order to correct this problem. You must also clean each bypass valve bore. Install new engine oil filters. New engine oil filters will prevent more debris from causing this pro