Page 34 - CTS - Mechanic Diesel - TP
P. 34

MECHANIC DIESEL - CITS


                                                             MODULE 2: Engine System


           EXERCISE 2.1: Perform vacuum test


            Objectives


           At the end of this exercise you shall be able to
           •  installing vacuum gauge
           •  testing the vacuum in different stages
           •  concluding the results.

           Requirements

           Tools/Materials

           •  A petrol vehicle in running condition
           •  Combination plier
           •  Vacuum gauge

            Introduction

           The vacuum test is performed in an engine to know the condition of the engine and with the results we can have
           a conclusion of whether the engine need reconditioning or not.

           Procedure


           •  Place the vehicle in a level ground.
           •  Switch off engine.
           •  Open the bonnet.

           •  Locate the vacuum line in the engine intake manifold.
           •  Disconnect the vacuum connection from the component where it is connected and not from the intake manifold
           •  Connect the vacuum gauge with the vacuum line.
           •  Start the engine.
           •  Allow the engine to run idle.
           •  Note  down  the  reading  shown  in  the  vacuum
              gauge.
           •  The vacuum of the engine during idle is _________
              in- Hg.

           •  Slowly  raise  the  engine  till  the  engine  speed
              reaches  approximately  2500  rpm. And  measure
              the vacuum again.
           •  The vacuum during 2500 rpm is _______ in-Hg.
           •  slow down the engine speed.
           •  Raise the engine speed suddenly and release it immediately.
           •  Note down the vacuum reading.

           •  The vacuum during sudden raise and release are ______ in Hg.
           •  Based on the readings obtained, conclude the condition of the engine.





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