TURBOCHARGER AS 3149972 - Caterpillar

Restriction Of Air Inlet And Exhaust
There will be a reduction in the performance of the engine if there is a restriction in the air inlet system or the exhaust system.The air flow through a used air cleaner may have a restriction. The air flow through a plugged air cleaner will be restricted to some amount. In either case, the restriction must not be more than the following amount:
7.5 kPa (30 in H2O)Back Pressure is the difference in the pressure between the exhaust at the outlet elbow and the atmospheric air. Back pressure from the exhaust must not be more than the following amount:
6.7 kPa (27 in H2O)Measurement Of Pressure In Inlet Manifold
Table 1
Tools Needed    
Part Number    Part Description    Qty    
1U-5470     Engine Pressure Group     1    The efficiency of an engine can be checked by making a comparison of the pressure in the inlet cover with the information in the Technical Marketing Information (TMI).This test is used when there is a decrease of horsepower from the engine, yet there is no actual sign of a problem with the engine.The correct pressure for the inlet manifold is also given in the Technical Marketing Information (TMI), "Fuel Setting and Related Information". These standards are established under the following conditions:
96 kPa (29 inches of Hg) dry barometric pressure
29°C (85°F) outside air temperature
35 API rated fuelAny change from these conditions can change the pressure in the inlet manifold. The outside air may have a higher temperature and a lower barometric pressure than the values that are given above. This will cause a lower inlet manifold pressure measurement than the pressure in the TMI. Outside air that has both a lower temperature and a higher barometric pressure will cause a higher inlet manifold pressure measurement.A difference in fuel density will change horsepower (stall speed) and boost. If the fuel is rated above 35 API, the pressure in the inlet manifold can be less than the pressure that appears in the TMI. If the fuel is rated below 35 API, the pressure in the inlet manifold can be more than the pressure that appears in the TMI. BE SURE THAT THE AIR INLET OR THE EXHAUST DOES NOT HAVE A RESTRICTION WHEN YOU ARE MAKING A CHECK OF THE PRESSURE.Note: The electronic service tool may be used to check the pressure in the inlet manifold.
Illustration 1 g00320614
Plugs for pressure test
Illustration 2 g00293196
1U-5470 Engine Pressure Group The 1U-5470 Engine Pressure Group and part of the 9U-7400 Multitach can be used to check the pressure in the inlet manifold.The 1U-5470 Engine Pressure Group has a gauge that indicates pressure inside the inlet manifold. Instructions for using this tool group appear in the Special Instructions, SEHS7851.
Illustration 3 g00300249
9U-7400 Multitach The 9U-7400 Multitach can measure engine speed from a tachometer drive on the engine. The 9U-7400 Multitach also has the ability to measure engine speed from visual engine parts in rotation.Measurement Of Exhaust Temperature
Table 2
Tools Needed    
Part Number    Part Description    Qty