PIN AS 4E3197 - Caterpillar

Restriction Of Air Inlet And Exhaust
If there is a restriction of the air inlet or of the exhaust system, horsepower and engine efficiency will be reduced. Back pressure from the exhaust (pressure difference measurement between turbocharger exhaust outlet and atmosphere) must not be more than 686 mm (27 inches of H2O) for turbocharged engines.Measurement Of Exhaust Temperatures
Use the 1U-8865 Infrared Thermometer to check exhaust temperature. Instructions for the test procedures can be found in Special Instruction SEHS8149. These instructions are included with the infrared thermometer.Checking Aftercooler Operation
Use the 4C-6500 Thermistor to check the operation of the aftercooler.Refer to Special Instruction, SEHS8446 for more information about the 4C-6500 Thermistor .Turbocharger
Inspect the bearing for the turbocharger. This bearing should be inspected after 7200 hours or service. This check should also be made if any unusual sound or vibration is noticed in the turbocharger. The turbocharger does not need to be disassembled in order to perform this quick check. Remove the piping from the turbocharger and inspect the compressor impeller. Inspect the turbine wheel and the compressor cover. Rotate the compressor and turbine wheel assembly by hand. Observe the compressor and the turbine wheel by feeling for excess end play and radial clearance. The rotating assembly should rotate freely with no rubbing or binding. The impeller should not rub against the compressor cover. The turbine wheel should not rub against the turbine housing. The turbocharger must be reconditioned, replaced, or rebuilt when any of the above conditions exist.End clearance should be checked with a dial indicator. Attach a dial indicator with the indicator point on the end of the shaft. Move the shaft from one end to the other end. Take note of the total reading on the indicator.End play for the turbocharger should be 0.08 to 0.25 mm (.003 to .010 inch). If the end play is more than the maximum end play, the turbocharger should be rebuilt or replaced. If the end play is less than the minimum end play, carbon may be built up on the turbine wheel. If this is the case, the turbocharger should be disassembled for cleaning and inspection.
Illustration 1 g00320945
Typical example of checking the end play of the turbochargerA more reliable check of the bearing conditions can be made only when the turbocharger is disassembled. The bearings, the shaft journal, and the housing bore diameters can accurately be measured when the turbocharger is disassembled.
Illustration 2 g00320963
Checking turbocharger radial clearance (typical example)Radial clearance can also be checked with a dial indicator. Remove the oil return line from the turbocharger. Attach a dial indicator with an indicator point that is extended to the shaft. The indicator point must be extended to a length that will allow the dial indicator to contact the shaft through the oil return hole. Make sure that the contact point is centered on the shaft. This will provide the highest indicator reading. Raise both ends of the shaft upward. Push both ends of the shaft downward in the opposite direction. The total movement of