Cooling System and Belts Presentation 2020.pdf

Lecture PowerPoint® Slides to accompany Automotive Technology A Systems Approach Third Canadian Edition Prepared by Martin Restoule, Algonquin College Copyright © 2015 Nelson Education Ltd. Chapter 8 & 14 Cooling Systems...

Lecture PowerPoint® Slides to accompany Automotive Technology A Systems Approach Third Canadian Edition Prepared by Martin Restoule, Algonquin College Copyright © 2015 Nelson Education Ltd. Chapter 8 & 14 Cooling Systems and Accessory Drives Copyright © 2015 Nelson Education Ltd. 2  Automotive Technology: A Systems Approach, 3Ce LEARNING List and describe the major OUTCOMES: components of the cooling system. Describe the operation of the cooling system. Describe the function of the water pump, radiator, radiator cap, thermostat, and thermostat in the cooling system. Test and service the cooling system. Copyright © 2015 Nelson Education Ltd. 3  Automotive Technology: A Systems Approach, 3Ce In a liquid-cooled system, heat is removed from around the combustion chambers by coolant circulating inside the engine. This liquid is pumped through the engine then flows into the radiator where the heat is transferred to the atmosphere. Copyright © 2015 Nelson Education Ltd. 4  Figure 2 - Heat transfer by convection. © 2010, Her Majesty the Queen in right of the Province of Alberta  Automotive Technology: A Systems Approach, 3Ce Convection The movement of warm gases or liquids from a hot area to a cooler area. Hot air/liquid rises Cold air/liquid falls ie: convection oven, hot air balloon, wind currents Copyright © 2015 Nelson Education Ltd. 6  Figure 3 - Heat transfer by radiation. © 2010, Her Majesty the Queen in right of the Province of Alberta  Automotive Technology: A Systems Approach, 3Ce Radiation Radiant heat is from the dissipation of heat caused by vibrations in the molecular structure of an element. ie: Warm sun on your face, warming your hands over a hot exhaust manifold Copyright © 2015 Nelson Education Ltd. 8  Figure 4 - Heat transfer by conduction. © 2010, Her Majesty the Queen in right of the Province of Alberta  Automotive Technology: A Systems Approach, 3Ce Conduction Conduction is the transfer of heat from one molecule to another, within an object. ie: If you heat one end of a steel rod with a torch, you will soon feel heat on the other end of it – might want to use protective gloves! Copyright © 2015 Nelson Education Ltd. 10  Automotive Technology: A Systems Approach, 3Ce The Water Boy How does the basic cooling system function? https://www.youtube.com/watch?v=TK06UIb MD94 Copyright © 2015 Nelson Education Ltd. 11  Automotive Technology: A Systems Approach, 3Ce Engine coolant is actually a mixture of water and antifreeze/coolant. Water alone has a boiling point of 100°C (212°F) and a freezing point of 0°C (32°F) at sea level. A mixture of 67% antifreeze and 33% water will raise the boiling point of the mixture to 113°C (235°F) and lower the freezing point to –69°C (–92°F). The typical recommended mixture is 50/50. It is popular in some northern locations to use a 60% antifreeze and 40% water mixture for the extra freeze protection. Copyright © 2015 Nelson Education Ltd. 12  Automotive Technology: A Systems Approach, 3Ce Coolant facts A 50/50 mix offers freezing protection down to -34 degrees F or -37 degrees C. Open to atmosphere, it will boil at or around 225 F or 107 C. Minimum antifreeze concentration must be 44%, year round, regardless of climate, to prevent cavitation damage. See page 197 in text. Pure antifreeze freezes at around 5 degrees F/-15 C and boils around 197 C/ 387 F. Copyright © 2015 Nelson Education Ltd. 13  Figure 5 - The boiling point of a liquid increases with pressure. © 2010, Her Majesty the Queen in right of the Province of Alberta  Automotive Technology: A Systems Approach, 3Ce Pressure VS Temperature Water boils at 100 degrees C (212 F) at when under atmospheric pressure. The boiling point will increase by 1.6 C (3 F), for every 1 PSI placed on it in a closed system. Therefore, if a 50% antifreeze mixture at atmospheric pressure would boil at 225 F (107 C), a 15 lb cap should raise the boiling temp by 45 F to 270 F (131 C). Copyright © 2015 Nelson Education Ltd. 15  Automotive Technology: A Systems Approach, 3Ce Coolants Five types of coolant are commonly available: Ethylene glycol: This was once the most commonly used antifreeze. It uses inorganic acid technology (IAT), is green in colour, and provides good protection regardless of climate, but it is poisonous. IAT coolant is not compatible with newer long-life coolants. Copyright © 2015 Nelson Education Ltd. 16  Automotive Technology: A Systems Approach, 3Ce Coolants Propylene glycol: This type has the same basic characteristics as ethylene glycol–based coolant but is not sweet tasting and is less harmful to animals and children. Propylene glycol–based coolants are not used as factory-fill coolants and should not be mixed with ethylene glycol. Copyright © 2015 Nelson Education Ltd. 17  Automotive Technology: A Systems Approach, 3Ce Coolants Phosphate-free: This is ethylene glycol–based coolant with zero phosphates, which makes it more environmentally friendly. Phosphate-free coolant is recommended by some auto manufacturers. Organic acid technology (OAT): This coolant is also environmentally friendly and contains zero phosphates or silicates. This orange coolant is often referred to by the brand name DEX-COOL. Copyright © 2015 Nelson Education Ltd. 18  Automotive Technology: A Systems Approach, 3Ce Coolants Hybrid organic acid technology (HOAT): This is similar to OAT coolant but has additives that make the coolant less abrasive to water pumps. This type of coolant is used by Ford and Chrysler and is not compatible with IAT or OAT coolants. Note: In addition to the five commonly available types of coolant, many manufacturers require a specific coolant for their vehicles. Always refer to manufacturers’ specifications when replacing coolant. Do not rely on the colour as a definite identifier. Copyright © 2015 Nelson Education Ltd. 19  Automotive Technology: A Systems Approach, 3Ce DEXCOOL https://penray.com/wp- content/uploads/2012/12/01.010.pdf https://www.motor.com/magazine- summary/coolant-confusion-its-not-easy-being- green-or-yellow-or-orange-or/ Copyright © 2015 Nelson Education Ltd. 20  Automotive Technology: A Systems Approach, 3Ce PH – Acid VS Alkaline Copyright © 2015 Nelson Education Ltd.. 21  Automotive Technology: A Systems Approach, 3Ce The thermostat controls the minimum operating temperature of the engine. The maximum operating Insert Figure 14-20, 3Ce temperature is controlled by the amount of heat being produced by the engine at the time and the cooling system’s ability to dissipate the heat. Copyright © 2015 Nelson Education Ltd. 22  Automotive Technology: A Systems Approach, 3Ce The most common location of the thermostat used to be at the front top of the engine block. For years now, you will normally find the thermostat on the lower rad hose, where coolant re-enters the engine from the radiator. The heat element fits into a recess in the block where it is exposed to hot coolant. The top of the thermostat is then covered by the water outlet housing, which holds it in place and provides a connection to the upper (or lower) radiator hose. Copyright © 2015 Nelson Education Ltd. 23  Automotive Technology: A Systems Approach, 3Ce Reverse Flow Some vehicles are designed Cooling Systems with a reverse flow cooling https://waterpumpu.com/blog-how- the-general-motors-lt1-reverse-flow- system, which directs the cooling-system-operates/ coolant through the heads first, instead of the block around the cylinders first.. Since the head(s) are the hottest item in the cooling system, cooling them first has many benefits. Copyright © 2015 Nelson Education Ltd. 24  Automotive Technology: A Systems Approach, 3Ce The thermostat when closed (A) permits fast warm-up of the engine. Thermostats must start to open (B) at a specified temperature normally 1.6°C (3°F) above or below its temperature rating. As the engine warms, the expanding wax in the pellet forces the poppet assembly downward from the piston. Copyright © 2015 Nelson Education Ltd. 25  Automotive Technology: A Systems Approach, 3Ce Just Open VS Fully Open The thermostat must be fully opened at about 11 degrees C (20 degrees F) above the start to open temperature. Copyright © 2015 Nelson Education Ltd. 26  Automotive Technology: A Systems Approach, 3Ce How Thermostats Are Made https://www.youtube.com/watch?v=htKMFgw dxI8 Copyright © 2015 Nelson Education Ltd. 27  Automotive Technology: A Systems Approach, 3Ce How Many Thermostats? Keep in mind, the vehicle you are working on may have more than 1 thermostat. 2009 Nissan Cube Copyright © 2015 Nelson Education Ltd. 28  Figure 44 - Checking the thermostat opening temperature. (Courtesy Honda Canada Inc.) © 2010, Her Majesty the Queen in right of the Province of Alberta  Automotive Technology: A Systems Approach, 3Ce The heart of the cooling system is the water pump. Its job is to move the coolant through the cooling system. Insert Figure 14-22, 3Ce Typically the water pump is driven by the crankshaft through pulleys and a drive belt. Some pumps may be driven off the camshaft. Copyright © 2015 Nelson Education Ltd. 30  Automotive Technology: A Systems Approach, 3Ce GM 5.7 LT1 Water Pump Drive Copyright © 2015 Nelson Education Ltd. 31  Automotive Technology: A Systems Approach, 3Ce Water pumps are centrifugal-type pumps with a rotating paddle- wheel-type impeller to move the coolant. The shaft is mounted in the water pump housing and rotates on bearings. At the drive end, the exposed end, a pulley is mounted to accept the belt. Copyright © 2015 Nelson Education Ltd. 32  Automotive Technology: A Systems Approach, 3Ce The radiator is basically a liquid-to-air heat exchanger, transferring heat from the engine to the air passing through it. The radiator itself is a Insert Figure 14-24, 3Ce series of tubes and fins (collectively called the core) that expose the heat from the coolant to as much surface area as possible. Copyright © 2015 Nelson Education Ltd. 33  Figure 10 - Two types of radiator core construction. (Reproduced with permission of Ford Motor Co.) © 2010, Her Majesty the Queen in right of the Province of Alberta  Figure 11 - Aluminum radiator. (Courtesy General Motors of Canada Limited) © 2010, Her Majesty the Queen in right of the Province of Alberta  Automotive Technology: A Systems Approach, 3Ce Attached to the sides or top and bottom of the core are plastic or aluminum tanks. Attached to the sides or top and bottom of the core are plastic or aluminum tanks. Copyright © 2015 Nelson Education Ltd. 36  Automotive Technology: A Systems Approach, 3Ce The radiator is usually based on one of two designs: In a cross-flow radiator, coolant enters on one side, travels through tubes, and collects on the opposite side. In a down-flow radiator, coolant enters the top of the radiator and exits at the bottom tank. In both radiator designs, the coolant movement is caused by the pressure differential created by the action of the water pump. Copyright © 2015 Nelson Education Ltd. 37  Automotive Technology: A Systems Approach, 3Ce Radiator caps keep the coolant from splashing out of the radiator. They also serve a very important role in keeping the coolant’s temperature within a desired range. They do this by allowing the coolant to operate under a specified pressurize when required. Copyright © 2015 Nelson Education Ltd. 38  Automotive Technology: A Systems Approach, 3Ce The pressure in the system is regulated by a pressure relief or vent valve in the radiator cap. The cap seals the upper and lower sealing surfaces of the neck. The pressure relief valve is compressed against the lower seal. Coolant pressure builds up as the temperature of the coolant rises and pushes against the pressure relief valve. The valve opens when the pressure reaches the pressure rating of the cap. Copyright © 2015 Nelson Education Ltd. 39  Automotive Technology: A Systems Approach, 3Ce Cap specifications require that the cap must not leak below the low limit of the pressure range and must open above the high limit. Pressure caps should always be tested for the proper pressure release level and checked for gasket cracking, brittleness, or deterioration each time the antifreeze is changed or when any routine cooling system maintenance is performed. Copyright © 2015 Nelson Education Ltd. 40  Automotive Technology: A Systems Approach, 3Ce Most cooling systems have an expansion or recovery tank. Expansion tanks are designed to catch and Insert Figure 14-28, 3Ce hold any coolant that passes through the pressure cap when the engine is hot. The cap will also allow coolant from the expansion tank to re-enter the cooling system. There are marks on most recovery tanks that show where coolant levels should be when the car is running and when it is not. Copyright © 2015 Nelson Education Ltd. 41  Automotive Technology: A Systems Approach, 3Ce Most vehicles have at least four hoses in the cooling system; some have five or more. Two small diameter hoses send hot coolant from the Insert Figure 14-29, 3Ce water pump to the heater core and back. Two larger diameter hoses move the coolant from the water pump to the radiator and back into the engine block. Copyright © 2015 Nelson Education Ltd. 42  Automotive Technology: A Systems Approach, 3Ce Water jackets are hollow passages in the block and cylinder heads that surround the areas closest to the cylinders and combustion chambers. Included in the water jackets are core plugs and a block drain plug. The core plugs and drain are usually removed during engine teardown. Copyright © 2015 Nelson Education Ltd. 43  Automotive Technology: A Systems Approach, 3Ce Original equipment hose clamps are usually spring steel wires that are removed and replaced with special pliers. A variety of replacement clamps may be used. The worm gear clamp is popular because it provides even clamping force around the hose. It is also easy to install and requires no special tools. Copyright © 2015 Nelson Education Ltd. 44  Automotive Technology: A Systems Approach, 3Ce A passenger compartment heater is part of the engine’s cooling system. Heated coolant flows from the engine through heater hoses and a heater control valve to a smaller heater core, located in a hollow housing on either side of the firewall. Air is directed or blown over the hot heater core, and the heated air flows into the passenger compartment. Copyright © 2015 Nelson Education Ltd. 45  Automotive Technology: A Systems Approach, 3Ce To eliminate this power drain during times when fan operation is not needed, many of today’s belt-driven fans operate only when the engine and radiator heat up. This is accomplished by a viscous-drive fan clutch. Copyright © 2015 Nelson Education Ltd. 46  Figure 29 - Temperature sensitive bimetallic spring on a thermostatic fan clutch. (Photographed at E-C Automotive Parts and Machining) © 2010, Her Majesty the Queen in right of the Province of Alberta  Figure 30 - Thermostatic fan clutch operation. © 2010, Her Majesty the Queen in right of the Province of Alberta  Figure 22 - Six-bladed flex fans. © 2010, Her Majesty the Queen in right of the Province of Alberta  Figure 23 - The blade pitch on a flex fan decreases with speed. © 2010, Her Majesty the Queen in right of the Province of Alberta  Automotive Technology: A Systems Approach, 3Ce In most late-model applications, to save power and reduce the noise level the conventional belt- driven, water-pump- mounted engine cooling fan has been replaced with a 12- volt motor-driven fan. Copyright © 2015 Nelson Education Ltd. 51  Automotive Technology: A Systems Approach, 3Ce With the engine coolant below approximately 101.6°C (215°F), the relay contacts are open and the fan motor does not operate. Should the engine coolant temperature exceed approximately 110°C (230°F), the engine coolant temperature switch closes. This energizes the fan relay coil, which in turn closes the relay contacts providing 12 volts to the fan motor. Copyright © 2015 Nelson Education Ltd. 52  Automotive Technology: A Systems Approach, 3Ce Caution! Electric cooling fans, on some cars, can activate at any time, regardless of if the car is running or not. In certain cases, the ignition does not even have to be on. Some will engage the fan after the vehicle is shut off to blow off excess heat since the water pump is no longer circulating the coolant. Copyright © 2015 Nelson Education Ltd. 53  Automotive Technology: A Systems Approach, 3Ce A coolant temperature indicator alerts the driver of an overheating condition. It consists of a temperature gauge and/or a light. A temperature sensor is installed into a water jacket. These indicate coolant temperatures to the driver and supply some important information to today’s computer-controlled engine control systems. Copyright © 2015 Nelson Education Ltd. 54  Automotive Technology: A Systems Approach, 3Ce The block heater is a small heating element much like the ones found on a typical electric range. This element can be installed into a water jacket by removing a core plug. Carefully place the element in a position so that it is not touching any part of the block. Copyright © 2015 Nelson Education Ltd. 55  Automotive Technology: A Systems Approach, 3Ce The cooling system must operate, be inspected, and be serviced as a system. Replacing one damaged part while leaving others dirty or clogged will not increase system efficiency. Insert Figure 14-38, 3Ce Lime and dirt buildup in the coolant passages tend to insulate the walls of the water jackets and can cause hot spots that result in increased wear and make overheating more likely. Copyright © 2015 Nelson Education Ltd. 56  Automotive Technology: A Systems Approach, 3Ce Danger!!! Before opening the cap on a warm cooling system, squeeze the upper rad hose to see if the system is still pressurized. If the hose is hard with pressure, let it cool down first. Pressurized hot coolant can explode into steam when the pressure is released. Copyright © 2015 Nelson Education Ltd. 57  Automotive Technology: A Systems Approach, 3Ce Cooling System Inspection Inspect all cooling system hoses for signs of leakage and/or damage. Replace all hoses that are swollen, are 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 radiator for any buildup of dirt and bugs. Copyright © 2015 Nelson Education Ltd. 58  Automotive Technology: A Systems Approach, 3Ce Coolant Inspection 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. Copyright © 2015 Nelson Education Ltd. 59  Automotive Technology: A Systems Approach, 3Ce Coolant Condition A coolant hydrometer can be used to check the amount of antifreeze in the coolant. When the squeeze bulb is squeezed and released, coolant is drawn into 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. Copyright © 2015 Nelson Education Ltd. 60  Automotive Technology: A Systems Approach, 3Ce Coolant Condition A refractometer offers a precise way to check coolant condition. A sample of the fluid is placed in the sample area of the meter, and as light passes through the sample, a line is cast on the meter’s scale. The line shows the concentration of the antifreeze in the coolant. Copyright © 2015 Nelson Education Ltd. 61  Automotive Technology: A Systems Approach, 3Ce Coolant Condition Copyright © 2015 Nelson Education Ltd. 62  Automotive Technology: A Systems Approach, 3Ce Coolant Condition Litmus strips can also be used to evaluate coolant. The test strips are immersed into a sample of coolant. The strip will change colour. The colour of the strip is then compared to a scale on the container of strips. Matching the colours will indicate the freeze protection level and the acidity of the coolant. Copyright © 2015 Nelson Education Ltd. 63  Automotive Technology: A Systems Approach, 3Ce A voltmeter is used to check for conditions that can cause electrolysis. Set the meter so that it can read in tenths of a volt DC. Attach the negative meter lead Insert Figure 14-39, 3Ce to a good ground. Place the positive lead into the coolant. Readings of 0 to 0.3 volt are normal for a cast-iron engines and readings for a bimetal or aluminum engine are half that amount. Copyright © 2015 Nelson Education Ltd. 64  Automotive Technology: A Systems Approach, 3Ce The most common cooling system problem is overheating. There are many reasons for this. Diagnosis of this condition involves many steps, simply because many things can cause this problem. Basically, overheating can be caused by anything that decreases the cooling system’s ability to absorb, transport, and dissipate heat. The first step is to determine whether the engine is indeed overheating. Copyright © 2015 Nelson Education Ltd. 65  Automotive Technology: A Systems Approach, 3Ce continued Copyright © 2015 Nelson Education Ltd. 66  Automotive Technology: A Systems Approach, 3Ce Effects of Overheating Engine overheating can cause the following problems: Detonation OHC cam seizure and Preignition breakage Blown head gasket Cylinder damage due to Blown hoses swelling pistons Radiator leaks Sticky exhaust valve stems Warped cylinder head Engine bearing damage Copyright © 2015 Nelson Education Ltd. 67  Automotive Technology: A Systems Approach, 3Ce Carefully check all cooling hoses for leakage, swelling, and chafing. Change any hose that feels mushy or extremely brittle when squeezed firmly. When a hose becomes soft, it is deteriorating and should be replaced before more serious problems result. When a hose is hard, it is brittle and should be replaced. Hard hoses resist flexing and may crack rather than bend. The result is a leak. Copyright © 2015 Nelson Education Ltd. 68  Automotive Technology: A Systems Approach, 3Ce Electrochemical degradation (ECD) is the primary cause of coolant hose failure. This occurs because the hose, engine coolant, and the engine/radiator fittings form a galvanic (battery) cell. This chemical reaction causes very small cracks in the hose, allowing the coolant to attack and weaken the reinforcement in the hose. Copyright © 2015 Nelson Education Ltd. 69  Automotive Technology: A Systems Approach, 3Ce When electric cooling fan(s) are not turning on, test each fan motor by connecting battery power to terminal 1 and a ground to terminal 2. Insert Figure 14-43, 3Ce If either motor fails to run or does not run smoothly, replace it. If the motor runs, the problem is in the motor’s control circuit. Copyright © 2015 Nelson Education Ltd. 70  Automotive Technology: A Systems Approach, 3Ce There are several ways to test the opening temperature of a thermostat. The easiest way to check thermostat operation is to measure engine temperature with an infrared thermometer. Copyright © 2015 Nelson Education Ltd. 71  Automotive Technology: A Systems Approach, 3Ce The majority of water pump failures are attributed to leaks of some sort. When the pump seal fails, coolant will begin to seep out of the weep hole in the Insert Figure 14-45, 3Ce casting. This is an early indicator of trouble. The seals may simply wear out due to abrasives in the cooling system. Copyright © 2015 Nelson Education Ltd. 72  Automotive Technology: A Systems Approach, 3Ce To check the operation of the water pump, start the engine and allow it to warm up. Squeeze the upper radiator Insert Figure 14-46, 3Ce hose and accelerate the engine. If a surge is felt in the hose, the pump is working. Copyright © 2015 Nelson Education Ltd. 73  Automotive Technology: A Systems Approach, 3Ce A pressure tester is used to identify cooling system leaks. Connect the tester and run the engine until it is warm. Pump the handle until the gauge reads the radiator cap rating. Watch the gauge for pressure drops; carefully check the hoses, radiator, heater core, and water pump for leaks. Copyright © 2015 Nelson Education Ltd. 74  Automotive Technology: A Systems Approach, 3Ce A coolant leak can be found by a thorough visual inspection or the use of a dye penetrant. Visually, the leak may show wet or have a light grey colour. Insert Figure 14-48, 3Ce When using dye penetrant, a black light is used to illuminate the leaked dye. Where the dyed coolant leaks, a bright or fluorescent green colour will be seen. Copyright © 2015 Nelson Education Ltd. 75  Automotive Technology: A Systems Approach, 3Ce A combustion leak tester is used to determine whether combustion gases are entering the cooling system. This tester is basically a glass tube with a rubber bulb. The tube is fit with a one- way valve at the bottom that allows vapours to be drawn into the tester from the filler neck area. Copyright © 2015 Nelson Education Ltd. 76  Automotive Technology: A Systems Approach, 3Ce To check for combustion gas leaks, follow this procedure: Start the engine and allow it to reach normal operating temperature. Make sure the coolant level in the radiator is below the lower sealing area of the filler neck. Place the tester’s tube into the filler neck and rapidly squeeze and release the rubber bulb. This will force air from the radiator up through the test fluid. Observe the liquid. Combustion gases will change the colour of the liquid to yellow. If the liquid remains blue, combustion gases were not present. Copyright © 2015 Nelson Education Ltd. 77  Automotive Technology: A Systems Approach, 3Ce To test a radiator pressure cap for proper operation, apply the proper cap testing adapter and radiator pressure cap to the pressure tester head. Pump the tester until the Insert Figure 14-50, 3Ce pressure valve of the cap releases pressure. The cap should hold pressure in its range as indicated on the tester gauge dial for one minute. If not, replace it. Copyright © 2015 Nelson Education Ltd. 78  Automotive Technology: A Systems Approach, 3Ce All cooling system hoses are basically installed the same way. The hose is clamped onto inlet-outlet nipples on the radiator, water pump, and heater. Replacement radiator Insert Figure 14-51, 3Ce hoses must be the correct diameter, length, and shape. Each has a part number, which is often printed on the old hose and on the hose package. Copyright © 2015 Nelson Education Ltd. 79  Automotive Technology: A Systems Approach, 3Ce When replacing a hose, drain the coolant system below the level being worked on. Loosen or carefully cut the old clamp. Then, using a knife, carefully cut the end of the old hose so that it can slide off its fitting. If the hose is stuck, do not pry it off. You could possibly damage the inlet/outlet nipple or the attachment between the end of the hose and the bead. Copyright © 2015 Nelson Education Ltd. 80  Automotive Technology: A Systems Approach, 3Ce When replacing a hose, dip the ends in coolant to lubricate it and slip new clamps over each end. Slip the hose over its fittings, engine end first. Then, slide the clamps to about 6.4 mm (1⁄4 in.) from the end of the hose after it is properly positioned on the fitting. Tighten the clamp securely but do not overtighten. Copyright © 2015 Nelson Education Ltd. 81  Automotive Technology: A Systems Approach, 3Ce Thermoplastic hose clamps can also be used. These heat-sensitive clamps are installed on the hose ends and a heat gun is used to shrink the clamp. The shrinking of the clamp tightens the connection. As the engine runs, the heat of the coolant further tightens the connection. Copyright © 2015 Nelson Education Ltd. 82  Automotive Technology: A Systems Approach, 3Ce When replacing the thermostat, also replace the gasket that seals the thermostat in place and is positioned between the water outlet casting Insert Figure 14-55, 3Ce and the engine block. Make sure the mating surfaces on the housing and block are clean and free of old gasket material. Copyright © 2015 Nelson Education Ltd. 83  Automotive Technology: A Systems Approach, 3Ce Normally, there are locating pins on the thermostat that are used to position the thermostat in the block and housing. Insert Figure 14-56, 3Ce Copyright © 2015 Nelson Education Ltd. 84  Automotive Technology: A Systems Approach, 3Ce Part of a preventive maintenance program is changing the engine’s coolant. This is done to prevent the coolant from breaking down chemically. When this happens, the coolant becomes too acidic. Most radiators have a drain plug located in the lower part of a tank. Some have a petcock valve. Make sure the engine is cool before draining the coolant. Copyright © 2015 Nelson Education Ltd. 85  Automotive Technology: A Systems Approach, 3Ce Additional coolant can be drained through drain plugs in the engine block. Place the catch can below the drain plug and Insert Figure 14-57, 3Ce remove the plug. Once the coolant has drained, replace the plug. Make sure to apply sealer on the threads of the plug. Copyright © 2015 Nelson Education Ltd. 86  Automotive Technology: A Systems Approach, 3Ce Coolant Flushing Old “green” IAT coolant should be flushed or changed every 2 years. DexCool and other OAT coolants recommend flushing every 5 years. Some newer vehicles with OAT or HOAT coolant, recommend even longer intervals or lifetime. Copyright © 2015 Nelson Education Ltd.. 87  Automotive Technology: A Systems Approach, 3Ce CAUTION!! Automotive coolant is poisonous. Do not leave it out where children, animals or not – so – smart people might drink it. Do not pour it down the drain either. It needs to be collected and recycled! Copyright © 2015 Nelson Education Ltd. 88  Automotive Technology: A Systems Approach, 3Ce Flushing If using a flushing gun, drain the rad and block, remove the thermostat if feasible (perhaps a good time to recommend a new one). Thoroughly flush the entire system, including the reservoir. Drain everything and blow remaining water out of the system Copyright © 2015 Nelson Education Ltd. 89  Automotive Technology: A Systems Approach, 3Ce Reverse flushing is the procedure of forcing clean liquid backwards through the cooling system. This carries away rust, scale, corrosion, and other contaminants. A flushing gun that operates on compressed air is used to force clean water and air through the system. This is not recommended for plastic or aluminum radiators. Copyright © 2015 Nelson Education Ltd. 90  Automotive Technology: A Systems Approach, 3Ce After the cooling system has been drained and all services performed, the system needs to be refilled with the proper type and mixture of coolant. When refilling the system, be Insert Figure 14-59, 3Ce sure you get it completely full. Some systems are difficult to fill without trapping air. Some engines have air bleed valves located at the high point in the system. Copyright © 2015 Nelson Education Ltd. 91  Automotive Technology: A Systems Approach, 3Ce Flushing Do not mix the coolant in a container to pour into the system. You have no idea how much water could be hiding in the system still!! Find the cooling system capacity. If you desire a 60/40 (60%) antifreeze/water mixture, multiply the capacity by 0.6. That will tell you what 60% of the system capacity is. (If you want 50/50 mix, multiply by 0.5, but allow for trapped water) Copyright © 2015 Nelson Education Ltd. 92  Automotive Technology: A Systems Approach, 3Ce Flushing Seal up the drains and pour the calculated amount of CONCENTRATED antifreeze into the coolant system, including some into the reservoir. Top off the system with pure (ideally distilled) water and run the vehicle till the air pockets have been purged out. Copyright © 2015 Nelson Education Ltd.. 93  Automotive Technology: A Systems Approach, 3Ce Concentrate VS Premixed Copyright © 2015 Nelson Education Ltd. 94  Automotive Technology: A Systems Approach, 3Ce Flushing Keep in mind…you can’t do the “garden hose” type flush if you only have premixed coolant. Your mixture will be guaranteed to be weak. If only premixed coolant is available, you can only perform a coolant “change”, (unless you have a flushing machine). Copyright © 2015 Nelson Education Ltd. 95  Figure 48 - Portable antifreeze recycling machine. © 2010, Her Majesty the Queen in right of the Province of Alberta  Automotive Technology: A Systems Approach, 3Ce Toyota hybrids have a system that heats a cold engine with retained hot coolant to provide reduced emissions levels. Hot coolant is stored in a container. The coolant will circulate through the engine immediately after startup. The fluid also may circulate through the engine many hours after it is shut off. Copyright © 2015 Nelson Education Ltd. 97  Automotive Technology: A Systems Approach, 3Ce The Toyota hybrid’s cooling system is also tied into the converter/inverter assembly. This also presents a Insert Figure 14-60, 3Ce potential problem, because it is easy to trap air in the cooling system due to the path of coolant flow. To purge the system of air, there is a bleeder screw and a scan tool is used to run the electrical water pump. Copyright © 2015 Nelson Education Ltd. 98  Automotive Technology: A Systems Approach, 3Ce Ford hybrids have two separate cooling systems: One is for engine cooling and the other is for hybrid components, called the motor electronics (M/E) cooling system. The M/E cooling system uses an electric water pump for coolant circulation. Copyright © 2015 Nelson Education Ltd. 99  Automotive Technology: A Systems Approach, 3Ce In Ford hybrids, the engine cooling system is conventional. The M/E cooling system uses an electric water pump to move coolant through the inverter, transmission, and a separate radiator mounted next to the conventional radiator. Copyright © 2015 Nelson Education Ltd. 100  Automotive Technology: A Systems Approach, 3Ce It is easy to trap air in the M/E cooling system when filling the system. The system is fitted with a bleeder screw at the top of the inverter. When servicing the system, make sure the high- voltage system is isolated by having the service connector in the SERVICING/SHIPPING position. Also, wear lineman’s gloves because the bleeder screw is very close to the high- voltage cables. Copyright © 2015 Nelson Education Ltd. 101  Automotive Technology: A Systems Approach, 3Ce A coolant exchanger is used to remove old coolant from the system and to put in new coolant at the correct mixture. Some coolant exchangers will also leak test the system and flush it. Coolant exchangers are normally powered by shop air, although a few are powered by the vehicle’s battery. Most exchangers move through their cycles with the engine off. Copyright © 2015 Nelson Education Ltd. 102  Automotive Technology: A Systems Approach, 3Ce Accessory Drive and Belts Copyright © 2015 Nelson Education Ltd.. 103  Automotive Technology: A Systems Approach, 3Ce Drive Belts V-belts and V-ribbed (serpentine) belts are used to drive water pumps, power-steering pumps, air conditioning compressors, generators, and emission control pumps. The angled sides of V-belts 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. Copyright © 2015 Nelson Education Ltd. 104  Automotive Technology: A Systems Approach, 3Ce Drive Belt Inspection Heat has adverse effects on drive belts; it can cause the belts to harden and crack. Excessive heat normally comes from slippage. Slippage can be caused by improper belt tension or oily conditions. 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 pulleys for rust, oil, wear, and other damage. Copyright © 2015 Nelson Education Ltd. 105  Figure 37 - Damaged drive belts. © 2010, Her Majesty the Queen in right of the Province of Alberta  Automotive Technology: A Systems Approach, 3Ce Drive Belt Inspection Copyright © 2015 Nelson Education Ltd. 107  Automotive Technology: A Systems Approach, 3Ce Drive Belt Tension A quick check of a belt’s tension can be made by locating the longest span of the belt between two pulleys. Press on the belt midway through this distance. If the belt moves more than 1.25 cm per 30 cm of free span, the belt should be adjusted. Different belts may require different tensions. The belt’s tension should be checked with a belt tension gauge. Copyright © 2015 Nelson Education Ltd. 108  Automotive Technology: A Systems Approach, 3Ce V-Ribbed Belts Most late-model vehicles use a V-ribbed or multi- ribbed belt to drive all or most accessories. Multi-ribbed belts are long and follow a complex path that weaves around the various pulleys and are also called serpentine belts. Proper tension is critical due to the complex routing. Copyright © 2015 Nelson Education Ltd. 109  Automotive Technology: A Systems Approach, 3Ce Belt Tensioners Over time, the belts will stretch and lose their tension. To compensate for this and to keep a proper amount of belt tension, serpentine belt systems have an automatic belt tensioner pulley. This pulley is a spring-loaded pulley that exerts a predetermined amount of pressure on the belt to keep it at the desired tension. Copyright © 2015 Nelson Education Ltd. 110  Automotive Technology: A Systems Approach, 3Ce Ribbed Belt Inspection Neoprene belts are dependable for up to 100 000 km. Through use they begin to develop cracks, uneven rib wear, edge and backside wear, glazing, and noise. If any of these are evident during an inspection of the belt, the belt should be replaced. Copyright © 2015 Nelson Education Ltd. 111  Automotive Technology: A Systems Approach, 3Ce Gates Belts Helpful Tips https://www.youtube.com/watch?v=GZvPMn E50UM https://www.gatestechzone.com/en/problem- diagnosis/accessory-drive-system/micro-v- belt-wear-symptoms https://assets.gates.com/content/dam/gates/ home/resources/resource-library/tech-tips- bulletins/tt002-15.pdf Copyright © 2015 Nelson Education Ltd. 112  Automotive Technology: A Systems Approach, 3Ce Gates Belts Tips cont. https://www.youtube.com/watch?v=g7oce8U 81K4 https://www.youtube.com/watch?v=xhYItqwA beg https://www.youtube.com/watch?v=fh5_92ZT aY0 Copyright © 2015 Nelson Education Ltd. 113  Automotive Technology: A Systems Approach, 3Ce Belt Replacement If a drive belt is damaged, it should be replaced. If there is more than one drive belt, all should be replaced even if only one is bad. Always use an exact replacement belt. The size of a new belt is typically given, along with the part number, on the belt container. Copyright © 2015 Nelson Education Ltd. 114  Automotive Technology: A Systems Approach, 3Ce Copyright © 2015 Nelson Education Ltd. 115  Automotive Technology: A Systems Approach, 3Ce To help you gain a more complete knowledge of this subject area, a thorough review of this chapter in your textbook is recommended. Copyright © 2015 Nelson Education Ltd. 116