Automotive Mechanics Learning Guide #3 PDF

Institution Name Document No. ኢትዮ-ጣሊያን ፖሊቴክኒክ ኮሌጅ OF/EIPC/RO/036 ETHIO-ITALY POLYTECHNIC COLLEGE AUTOMOTIVE MECHANICS...

Institution Name Document No. ኢትዮ-ጣሊያን ፖሊቴክኒክ ኮሌጅ OF/EIPC/RO/036 ETHIO-ITALY POLYTECHNIC COLLEGE AUTOMOTIVE MECHANICS NTQF Level II Learning Guide #3 Unit of Competence: Perform minor Engine Electrical Systems Service Instruments Module Title: Performing minor Engine Electrical Systems Service LG Code: EIS AUM2 M02 LO3-01 TTLM Code: EIS AUM2 M04 0322 UNIT-3: Replace/Reassemble System Assemblies Page 1 of 8 Ministry of Labor and Skills Perform minor engine electrical Version -1 Author/Copyright system service September, 2022  InstructionSheet LG3: Replace/Reassemble System Assemblies This learning guide is developed to provide you the necessary information regarding the followingcontent coverage and topics:  Carryout minor adjustments  Assembling system components  Conducting post-service/pre-delivery check This guide will also assist you to attain the learning outcome stated in the cover page. Specifically, upon completion of this Learning Guide, you will be able to:  Carry out minor adjustments  Assemble system components  Conduct post-service/pre-delivery check. Learning Activities: 1. Read the specific objectives of this Learning Guide. 2. Read the information written in the “Information Sheets” in pages-2. 3. Accomplish the “Self-check 3” in page 71. 4. Your teacher will evaluate your output either satisfactory or unsatisfactory. If unsatisfactory, your teacher shall advice you on additional work. But if satisfactory you canproceed to Learning Guide  Your teacher will evaluate your output either satisfactory or unsatisfactory. If unsatisfactory, your teacher shall advice you on additional work. But if satisfactory you canproceed to the next topic Page 2 of 8 Ministry of Labor and Skills Perform minor engine electrical Version -1 Author/Copyright system service September, 2022  Instruction Sheet LG3: Replace/Reassemble System Assemblies Unit Three Replace/Reassemble System Assemblies 1.1 Carrying out minor adjustments Whenever you change an engine’s oil, you should also do a visual inspection of the different systems under the hood, including the cooling system. Inspect all cooling system hoses for signs of leakage and/or damage. Replace all hoses that are swollen, cracked, or show signs of leakage. The radiator should also be checked for signs of leaks; if any are evident the radiator should be repaired or replaced. Also, check the front of the radiator for any build-up of dirt and bugs. This can restrict airflow through the radiator and should be removed by thorough cleaning. The level and condition of the engine’s coolant should also be checked. Check the coolant’s level at the coolant recovery tank. It should be between the “low” and “full” lines. If the level is too low, more coolant should be added through the cap of the tank, not the radiator. Bring the level up to the “full” line. Always use the correct type of coolant when topping off or replacing it. Look at the color of the coolant when checking the level. It should be green, or perhaps orange, but it should not look rusty or cloudy. If the coolant looks contaminated, the cooling system should be flushed and new coolant put into the system. 1.1.1 Coolant Condition A coolant hydrometer is used to check the amount of antifreeze in the coolant. This tester contains a pickup hose, coolant reservoir, and squeeze bulb. The pickup hose is placed in the radiator coolant. When the squeeze bulb is squeezed and released, coolant is drawn into the reservoir. As coolant enters the reservoir, a pivoted float moves upward with the coolant level. A pointer on the float indicates the freezing point of the coolant on a scale located on the reservoir housing. 1.1.2 Drive Belts Drive belts have been used for many years. V-belts and V-ribbed (serpentine) belts are used to drive water pumps, power steering pumps, air-conditioning compressors, generators, and Page 3 of 8 Ministry of Labor and Skills Perform minor engine electrical Version -1 Author/Copyright system service September, 2022  emission control pumps. Heat has adverse effects on drive belts and they tend to over cure due to excessive heat. This causes the rubber to harden and crack. Excessive heat normally comes from slippage. Slippage can be caused by improper belt tension or oily conditions. When there is slippage, heat also travels through the drive pulley and down the shaft to the support bearing of the component it is driving. These bearings may be damaged if the slippage is allowed to continue. V-belts ride in a matching groove in the engine’s pulleys. The angled sides of the belt contact the inside of the pulleys’ grooves. This point of contact is where motion is transferred. As a V-belt wears, it begins to ride deeper in the groove. This reduces its tension and promotes slippage. Because this is a normal occurrence, periodic adjustment of belt tension is necessary. Drive belts can be used to drive a single part or a combination of parts. An engine can have three or more V-belts. In some cases, two matched belts are used on the same pulley set. This increases the strength of the belt and pulley connection and provides redundancy in case a belt breaks. A. Inspection Even the best drive belts last only an average of 4 years. That time can be shortened by several things; most of these can be found by inspecting the belts. Check the condition of all of the drive belts on the engine. Carefully look to see if they have worn or glazed edges, tears, splits, and signs of oil soaking. If these conditions exist, the belt should be replaced. Also inspect the grooves of the drive pulleys for rust, oil, wear, and other damage. If a pulley is damaged, it should be replaced. Rust, dirt, and oil should be cleaned off the pulley before installing a new belt. Misalignment of the pulleys reduces the belt’s service life and brings about rapid pulley wear, which causes thrown belts and noise. Undesirable side or end thrust loads can also be imposed on pulley or pump shaft bearings. Check alignment with a straightedge. Pulleys should be in alignment within 1⁄16 inch (1.59 mm) per foot of the distance across the face of the pulleys. B. Belt Tension A quick check of a belt’s tension can be made by locating the longest span of the belt between two pulleys. With the engine off, press on the belt midway through that distance. If the belt moves more than ½ inch per foot of free span, the belt Page 4 of 8 Ministry of Labor and Skills Perform minor engine electrical Version -1 Author/Copyright system service September, 2022  should be adjusted. Keep in mind that different belts require different tensions. The belt’s tension should be checked with a belt tension gauge. The tension should meet the manufacturer’s specifications. Many engines are now equipped with a ribbed v-belt, which has an automatic tensioning pulley; therefore, a tension adjustment is not required. Using service information proper belt tightening procedures and specifications are given in the specification section of most service manuals. Figure Error! No text of specified style in document.-1 checking Belt Page 5 of 8 Ministry of Labor and Skills Perform minor engine electrical Version -1 Author/Copyright system service September, 2022  1.2 Assembling system components Connect the injector nozzle leak off pipe assembly Connect the cooling system Connect the exhaust pipe Connect the injector nozzle leak off pipe assembly Connect the fuel pipes from the fuel injection pump outlet and inlet to filter Connect fuel pipe from fuel lift pump outlet to fuel filter. Remove fuel filter Connect high pressure fuel pipes and nozzles Connect fuel pipe and electrical lead at the thermostat. Connect air filter and / or connecting hose Connect induction and exhaust manifold Connect the cooling system Connect fuel pipe and electrical lead at the thermostat. Remove air filter and / or connecting hose Remove induction and exhaust manifolds 1.3 Conducting post-service/pre-delivery check 1.3.1 Document result with evidence Documentation provides valuable descriptions of an organization’s development, acquisition, and operating environments and significantly enhances an organization’s ability to administer, operate, and maintain technology systems. Primary advantages for technicians’ involve having access to operation manuals and on-line application help features. Documentation enhances administrators’ and technicians’ ability to maintain and update systems efficiently and to identify and correct programming defects. Developing and maintaining current, accurate documentation can be complicated, time consuming, and expensive. However, standardized documentation procedures and the use of automated documentation software can facilitate an organization’s ability to maintain accurate documentation. Page 6 of 8 Ministry of Labor and Skills Perform minor engine electrical Version -1 Author/Copyright system service September, 2022  1.3.2 Final Inspection Consumers’ expectations are that they will receive their vehicle back in a serviceable condition and in a better operational condition than when it was delivered to the workshop. This expectation requires two (2) critical components:  A final inspection must be completed by the service technician to ensure that all of the protective features for the braking system have been refitted is replaced to the required specifications; and  A final inspection must be completed by the service technician to ensure that all of the work that was commenced on the system was completed to workplace, customer and manufacturers expectations. 1.3.3 Service provision There are some tasks that a technician will not carry out frequently. It would be unrealistic for a technician to have a detailed knowledge of seldom-performed procedures. In these circumstances, job cards or checklists are very useful as they give a step-by-step guide to follow whenever the rarely-used procedure needs to be performed. The required knowledge is often kept in manuals which may not be easily accessible. However, going through a large manual, possibly in front of a customer, does nothing for time effectiveness or professional image. A job card is also used as the basis of a recording process for the organization. In addition to refreshing the process for the technician it will be a list of the workplace expectations as well. It is suggested that the final task on a job card will be to ensure that the equipment is cleaned for use or storage. 1.3.4 Noting and documenting observations during the service The most precise way to document instruction is to create a Running Record, or virtual transcript, noting what was observed every two minutes. Direct observation of behaviors is important for many reasons. It is a means of generating hypotheses and new ideas or a means of answering specific questions. Observations also enable us to answer questions about what happens during repairing. For the purpose of these observations, time sampling is used to record engine parts repairing. Page 7 of 8 Ministry of Labor and Skills Perform minor engine electrical Version -1 Author/Copyright system service September, 2022  An observer should attend to all contextual details on the parts of engine repair. Observers do not make any assumptions at any time. They do not assume that any event is instructionally relevant or irrelevant. Observers should avoid biases based on personal preferences or practice. That is, when assigned to observe a particular instructional program, observers do not judge the engine parts or specific activities during repairing. Observers must record what kind of an engine part is repaired without making ongoing judgments about the quality of engine part repairing or the effective use of a particular technique. The observer’s job is to capture what happened, not his or her opinion of what happened. After noting and documenting the observation during the repair every technician should complete work shop practice schedule documentation. Follow these three general principles to develop records and documents: 1. Keep it short and simple. Use bullet points and flow diagrams instead of long sentences and lengthy paragraphs. 2. Clarity is important. Step-by-step instructions are easily understood. 3. Use a standardized, consistent format. Although different programs may need different documents and records, using a similar approach will help staff learn quickly. 1.3.5 Completing and delivering report to appropriate person Delivery is the process of transporting something/ like reports/ from a source location to a predefined destination after the work is done. The technician should be prepare a report and deliver to appropriate person. The reporting procedures are as follows  Record the work to be done  Inspect/test the repaired engine accordance with manufacturer procedure  Record/ capture the problem with the necessary information  Order the recorded problems /work done in accordance with their damaging area  Preparing reports have no error/discrepancy  Deliver reports to appropriate person. Page 8 of 8 Ministry of Labor and Skills Perform minor engine electrical Version -1 Author/Copyright system service September, 2022