SENSOR-TEMPERATURE 3341388 - Caterpillar

Symptom:1. Compressor passes excessive oil as evidenced by presence of oil at exhaust ports of valving or seeping from air strainer. Cause:A. Restricted air intake. Check engine or compressor air cleaner and replace if necessary. Check compressor air inlet for kinks, excessive bends and be certain inlet lines have the minimum specified inside diameter. Recommended minimum inlet line is 15.9 mm (5/8inch) ID. Recommended maximum air inlet restriction is 635 mm (25 inches) of water.B. Restricted oil return (to engine). Oil return to the engine should not be in any way restricted. Check for excessive bends, kinks and restrictions in the oil return line. Minimum recommended oil return line size is 15.9 mm (5/8inch) OD tubing or equivalent ID [12.7 mm (1/2 inch) minimum]. Return line must CONSTANTLY DESCEND from the compressor to the engine crankcase. Make certain oil drain passages in the compressor and mating engine surfaces are unobstructed and aligned. Special care must be taken when sealants are used with, or instead of, gaskets.C. Poorly filtered inlet air. Check for damaged, defective or dirty air filter on engine or compressor. Check for leaking, damaged or defective compressor air intake components (ie, induction line, fittings, gaskets, filter bodies, etc). The compressor intake should not be connected to any part of the exhaust gas recirculation (EGR) system on the engine.D. Insufficient compressor cooling (compressor runs hot). For air-cooled portions of the compressor:1. Remove accumulated grease, grime or dirt from the cooling fins. Replace components found damaged.2. Check for damaged cooling fins. Replace components found damaged.For water-cooled compressor or water-cooled portions of the compressor:1. Check for proper coolant line sizes. Minimum recommended size is 12.7 mm (1/2 inch) OD tubing.2. Check the coolant flow through the compressor. Minimum allowable flow is 9.5 liter/min (2.5 US gpm) at engine governed speed. If low coolant flow is detected, inspect the coolant lines and fittings for accumulated rust scale, kinks and restrictions.3. Water temperature should not exceed 93°C (200°F).4. Optimum cooling is achieved when engine coolant flow, as shown in Fig 8 of this manual.E. Contaminants not being regularly drained from system reservoirs. Check reservoir drain valves to insure that they are functioning properly. It is recommended that the vehicle should be equipped with functioning automatic drain valves, or have all reservoirs drained to zero (0) psi daily, or optimally to be equipped with a desiccant-type air dryer prior to the reservoir system.F. Compressor runs loaded an excessive amount of time. Vehicle system leakage should not exceed industry standards of 7 kPa (1 psi) pressure drop per minute without brakes applied and 20 kPa (3 psi) pressure drop per minute with brakes applied. If leakage is excessive, check for system leaks and repair.G. Excessive engine crankcase pressure. Test for excessive engine crankcase pressure and replace or repair ventilation components as necessary. (An indication of crankcase pressure is a loose or partially lifted dipstick).H. Excessive engine oil pressure. Check the engine oil pressure with a test gauge and compare the reading to