0319287 JOHNSON SEAL, Air silencer to carburetor

Measurement of Pressure In Inlet Manifold
Table 1
Tools Needed    
Part Number     Part Name     Quantity    
1U-5470     Engine Pressure Group     1    The efficiency of an engine can be checked by making a comparison of the pressure in the inlet manifold with the information given in the TMI (Technical Marketing Information). The information is also listed on the Fuel Setting And Related Information Microfiche. This test is used when there is a decrease of horsepower from the engine, yet there is no real sign of a problem with the engine.The correct pressure for the inlet manifold is listed in the TMI (Technical Marketing Information). The correct pressure is also on the Fuel Setting And Related Information Microfiche. Development of this information is performed under the following conditions:
99 kPa (29.7 in Hg) dry barometric pressure
29 °C (85 °F) outside air temperature
35 API rated fuelOn a turbocharged, aftercooled engine, a change in the fuel rating will change the horsepower. A change in the fuel rating will change the inlet manifold pressure. If the fuel is rated above 35 API, the inlet manifold pressure can be less than the pressure given in the TMI (Technical Marketing Information). The pressure will be less than the pressure listed on the Fuel Setting And Related Information Microfiche. If the fuel is rated below 35 API, the inlet manifold pressure can be more than the pressure listed in the TMI (Technical Marketing Information). The pressure can be more than the pressure that is listed on the Fuel Setting And Related Information Microfiche. Note: Ensure that the air inlet and the exhaust are not restricted when you are checking the inlet manifold pressure.
Illustration 1 g00434159
Pressure test location on inlet manifold (1) Plug
Illustration 2 g00293196
1U-5470 Engine Pressure Group To measure the inlet manifold pressure, remove plug (1) from the inlet manifold. Use the 1U-5470 Engine Pressure Group in order to check the inlet manifold pressure. The Special Instruction, SEHS8907 contains instructions for the tool.Exhaust Temperature
Table 2
Tools Needed    
Part Number     Part Name     Quantity    
123-6700     Laser Infrared Thermometer     1    Use the 123-6700 Laser Infrared Thermometer to check exhaust temperature. The Operator's Manual, NEHS0630 contains the complete operating and maintenance instructions for the 123-6700 Laser Infrared Thermometer .Air-To-Air Aftercooled Systems
Table 3
Tools Needed    
Part Number     Part Name     Quantity    
FT-1984     Aftercooler Testing Group     1    
FT-1438     Aftercooler (Dynamometer Test)     1    Visual Inspection
Inspect the following parts at each oil change:
Air lines
Hoses
Gasket joints
Pressurized air can cause personal injury. When pressurized air is used for cleaning, wear a protective face shield, protective clothing, and protective shoes.
Ensure that the constant torque hose clamps are tightened to the correct torque. Check the truck manufacturer's specifications for the correct torque. Check the welded joints for cracks. Ensure that the brackets are tightened in the correct positions. Ensure that the brackets are in good condition. Use compressed air to clean any debris or any dust from the aftercooler core assembly. Inspect the cooler core fins for the following conditions:
Damage
Debris
CorrosionUse a stainless steel brush to remove any corrosion. Ensure that you use soap and water.Note: When parts of the air-to-air aftercooler system are repaired, a leak test is recommended. When parts of the air-to-air aftercooler system are replaced, a leak test is recommended.The use of winter fronts or shutters is discouraged with air-to-air aftercooled systems. Winter fronts can only be used on certain truck models. On these trucks, tests have shown that the engine jacket water will overheat before the inlet manifold air temperature is excessive. These trucks use sensors and indicators that are installed in order to indicate engine operating conditions before excessive inlet manifold air temperatures are reached. Check with the truck manufacturer about the use of both winter fronts and shutters.Air System Restriction
Pressure measurements should be taken at the turbocharger outlet and at the inlet manifold. The air lines and the cooler core must be inspected for internal restriction when both of the following conditions are met:
Air flow is at a maximum level.
Total air pressure drop of the charged system exceeds 13.5 kPa (4 in Hg).If a restriction is discovered, proceed with the following tasks, as required:
Clean
Repair
Replacement