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COOLING SYSTEMS AUTO 1 If you did your homework, this will make more sense! If you didn’t, get it turned late tomorrow. We will take notes in a little bit.
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WHAT MAKES AN ENGINE RUN? NO! WHAT REALLY MAKES AN ENGINE RUN? HEAT
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WHERE DOES THE HEAT COME FROM? HEAT CAUSES EXPANSION WHICH CAUSES? PRESSURE PUSHES PISTON DOWN WHICH MAKES THE WHEELS GO ROUND AND ROUND PRESSURE! ENERGY………. THAT’S RIGHT, BURNING FUEL
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TYPES OF ENERGY ELECTRICAL CHEMICAL NUCLEAR THERMAL RADIANT MECHANICAL
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FUEL IS CHEMICAL ENERGY –WHEN BURNED COVERTS TO... THERMAL ENERGY (HEAT) –WHICH CAUSES EXPANSION (PRESSURE) –WHICH COVERTS TO… MECHANICAL ENERGY –WHICH WE USE TO MOVE THINGS THIS IS ENERGY CONVERSION
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ENERGY CONVERSION? REMEMBER, YOU CAN’T CREATE OR DESTROY ENERGY YOU CAN ONLY CHANGE ITS FORM –THIS IS ENERGY CONVERSION IN OTHER WORDS, THERE IS ONLY SO MUCH ENERGY HERE ON EARTH AND WE CAN’T ADD TO IT OR RUN OUT OF IT. NEVER USE IT UP! WOW
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WE HAD BETTER WRITE THIS DOWN IN OUR FUEL NOTES. FUEL IS CHEMICAL ENERGY –WHEN BURNED COVERTS TO... THERMAL ENERGY (HEAT) –WHICH CAUSES EXPANSION (PRESSURE) –WHICH COVERTS TO… MECHANICAL ENERGY –WHICH WE USE TO MOVE THINGS
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YOU CAN’T CREATE OR DESTROY ENERGY, YOU CAN ONLY CHANGE ITS FORM! ITS FORM IS CHANGED BY A CHEMICAL REACTION. THE MOST COMMON TYPE OF CHEMICAL REACTION IS COMBUSTION LETS MOVE ON
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LETS CONCENTRATE ON WE HAD BETTER WRITE THESE DOWN IF WE DON’T ALREADY KNOW THEM HEAT IS THE RAPID MOVEMENT OF ATOMS OR MOLECULES IN A SUBSTANCE ABSOLUTE 0 IS-460F (-273C) HEAT IS A FORM OF ENERGY HEAT IS MEASURED BY………. –TEMPERATURE DEGREES IN FAHRENHEIT OR CELSIUS –BTU’s VOLUME OF HEAT HEAT
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BTU,s ???? BRITISH THERMAL UNIT –ONE (1) BTU WILL RAISE THE TEMPERATURE OF ONE (1) POUND OF WATER ONE (1) DEGREE FAHRENHEIT (F)
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WHAT IS THE DIFFERENCE BETWEEN TEMPERATURE AND BTU,s ? TEMPERATURE IS THE DEGREE OF HEAT OR HOW HOT. –FOR EXAMPLE, A MATCH MIGHT BURN AT 400 DEGREES F. BTU IS THE VOLUME OF HEAT OR HOW MUCH, BUT NOT TEMPERATURE. –EXAMPLE, THE AMOUNT HEAT IT TAKES TO HEAT THIS ROOM, OR RAISE THE TEMPERATURE OF THIS ROOM
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COMBUSTION TEMPERATURES CAN REACH UP TO __________ DURNING THE COMBUSTION PROCESS. PAGE 92 OF YOUR HOMEWORK. THINK ABOUT THIS QUESTION BEFORE YOU FORM AN ANSWER. WOULD YOU WANT THE VOLUME OF HEAT FROM ONE 6000 DEGREE F POWER STROKE TO HEAT THIS ROOM? NOT IN THE WINTER TIME
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DO WE HAVE THE IDEA OF THE DIFFERENCES BETWEEN TEMPERATURE OF HEAT AND VOLUME OF HEAT?
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GALLON OF GASOLINE ONE GALLON OF GASOLINE HAS APPROXIMATELY 115,000 BTU,s. THAT MEANS THE AVERAGE GALLON OF GASOLINE HAS THE ENERGY TO RAISE THE TEMPERATURE OF ONE POUND OF WATER 115,000 DEGREES F. (IMPOSSIBLE) OR… RAISE 115,000 LBS OF WATER ONE DEGREE F. OR RASIE 1,150 LBS OF WATER (ABOUT 150 GALS.) 100 DEGREES F.
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OTHER FUELS HAVE DIFFERENT BTU,s DIESEL HAS APPROXIMAELY 135,000 BTU,s PER GALLON ALCOHOL HAS APPROXIMATELY 85,000 BTU,s PER GALLON
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HOW DOES THE ENGINE USE THIS ENERGY?
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ONE GALLON 115,000 BTU COST $1.30 - $1.60
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35% LOST OUT EXHAUST LOST TO EXHAUST
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35% LOST TO COOLING SYSTEM LOST TO EXHAUST LOST TO COOLING
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15% LOST TO FRICTIONAL LOSSES LOST TO EXHAUST LOST TO COOLING FRICTIONAL LOSSES
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APPROXIMATELY 15% LEFT TO MOVE THE CAR. LOST TO EXHAUST LOST TO COOLING FRICTIONAL LOSES WOW
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WHAT A WASTE!!!!!
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IF TODAYS VEHICLES CAN AVERAGE 20 MILES PER GALLON NOW USING JUST 15% OF THE ENERGY IN A GALLON OF FUEL... WHAT KIND OF MILAGE COULD THEY GET IF WE COULD IMPROVE IT TO 50% OF THE ENERGY IN A GALLON OF FUEL???
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TODAY –20 MPG USING 15% OF ENERGY TOMMOROW?? –70 MPG USING 50% OF ENERGY MILES PER GALLON AVERAGES
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SO WHY DO WE HAVE TO REMOVE 35% OF THE HEAT WITH A COOLING SYSTEM? LIMITED BY CURRENT MATERIAL TECHNOLOGY LIMITED BY CURRENT LUBRICATION TECHNOLOGY WE JUST PAID BIG MONEY TO BUY FUEL TO CREATE HEAT!
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CYLINDER WALL TEMPERATURE MUST BE KEPT BELOW 500 DEGREES F. WHY? OIL BREAKS DOWN (BURNS) CAN YOU SAY DRY FRICTION?
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HEAT TRANSFER MAKE SURE YOU GET THIS IN YOUR NOTES THE MOVEMENT OF HEAT FROM ONE PLACE TO ANOTHER
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THREE TYPES OF HEAT TRANSFER CONDUCTION CONVECTION RADIATION
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CONDUCTION TRANSFER OF HEAT THRU SOLIDS
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CONVECTION TRANSFER OF HEAT THRU LIQUIDS OR VAPORS
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RADIATION TRANSFER OF HEAT THRU LIGHT RAYS
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EXPERIMENT TIME
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DAY TWO
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LETS REVIEW CAN’T DESTROY OR CREATE ENERGY –ENERGY CONVERSION SIX TYPES OF ENERGY –IN AUTOMOBILES WE USE, ELECTRICAL, THERMAL, CHEMICAL, RADIANT, AND MECHANICAL. DON’T USE NUCLEAR HEAT –WHAT IT IS AND HOW IT IS MEASURED –DIFFERENCES BETWEEN TEMP AND BTU
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DIFFERENT FUELS HAVE DIFFERENT ENERGY CONTENT (BTU) TODAYS ENGINES ARE NOT VERY EFFICIENT
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APPROXIMATELY 15% OF THE ENERGY IN GASOLINE IS USED TO MOVE THE CAR. LOST TO EXHAUST LOST TO COOLING FRICTIONAL LOSES
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WHICH TYPE OF HEAT TRANSFER DO WE USE IN AN ENGINE? DURING COMBUSTION –EXPLOSION WOULD HAVE TRANSFER THRU RADIATION TO HEAD, CYLINDER WALL, AND TOP OF PISTON –ALSO TRANSFER THRU CONVECTION TO HEAD, CYLINDER WALL AND TOP OF PISTON and….
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FROM INSIDE OF CYLINDER WALL AND HEAD… –HEAT TRANSFER THRU CONDUCTION TO OUTSIDE OF CYLINDER WALL AND HEAD FROM OUTSIDE OF CYLINDER WALL AND HEAD… –HEAT TRANSFER THRU CONVECTION TO SURROUNDING AIR ON AIR COOLED TO SURROUNDING LIQUID IN WATER JACKET ON LIQUID COOLED
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SO WE USE ALL TYPES OF HEAT TRANSFER TO COOL AN ENGINE
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TYPES OF COOLING SYSTEMS AIR COOLED LIQUID COOLED
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LETS TAKE THE SIMPLE SYSTEM FIRST
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TYPES OF AIR COOLING FORCED DRAFT OPEN DRAFT WE WILL NEED THIS IN OUR NOTES
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FORCED DRAFT USUALLY USED ON ENGINES THAT ARE STATIONARY OR THAT AREN’T MOVED VERY FAST HAS A FAN TO FORCE AIR ACROSS ENGINE USES SHROUDS TO DIRECT AIR TO PROPER PLACES ALL YOUR ENGINES ARE FORCED DRAFT YOUR FLYWHEEL ACTS AS THE FAN
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LETS ADD THAT TO OUR ENGINE PARTS LIST PURPOSES FOR THE FLYWHEEL A. TO KEEP ENGINE MOVING THRU NON POWER STROKES B. ACTS AS A FAN FOR THE COOLING SYSTEM C. WE WILL GET D.C. AND D. LATER
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SHROUDS FOR FORCED DRAFT WHAT WOULD HAPPEN IF WE LEFT ONE OFF?
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NOTICE THE FINS. WHAT WOULD HAPPEN IF WE BROKE ONE OFF? THESE ARE CALLED HEAT DISAPATING FINS. THEY ADD SURFACE AREA SO MORE HEAT CAN BE REMOVED.
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LETS LOOK AT AN OPEN DRAFT AIR COOLED ENGINE HAS NO FAN ENGINE MUST MOVE THROUGH AIR FOR AIR MOVEMENT MAY OR MAY NOT HAVE SHROUDS TYPCIAL AIR COOLED MOTORCYCLE ENGINE
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REMEMBER ENGINE MUST MOVE THROUGH AIR TO GET PROPER COOLING ON THE OPEN DRAFT DESIGN! WITHOUT AIR MOVEMENT, ENGINE CAN OVERHEAT. ESPECIALLY ON HOT DAYS. MUST HAVE HEAT DISAPATING FINS AS WELL
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CHECK OUT THE HEAT DISAPATING FINS ON THIS CUT AWAY ENGINE.
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LETS MAKE SURE WE HAVE THIS IN OUR NOTES OPEN DRAFT –NO FAN, ENGINE HAS TO MOVE THRU AIR FOR COOLING FORCED DRAFT –HAS FAN TO FORCE AIR FLOW FOR COOLING SO WHAT DO WE NEED TO DO TO TAKE CARE OF AIR COOLING SYSTEMS ?
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AIR COOLING MAINTENANCE LETS MAKE SURE WE GET THIS IN OUR NOTES.
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KEEP FINS CLEAN OF GREASE AND DEBRIS –CLEAN WITH SOLVENT OR HOT SOAPY WATER OR CAN CLEAN WITH DEGREASERS –DON’T CLEAN WHILE ENGINE IS HOT –MAY HAVE TO REMOVE SOME SHROUDS TO GET TO ALL FINS KEEP ALL SHROUDS IN PLACE DURING USE
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FOR AIR COOLING MAINTENANCE IT IS THAT SIMPLE
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NEXT, WE ARE READY FOR LIQUID COOLING?
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LIQUID COOLING HERE WE COME!
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LIQUID COOLING IS MUCH MORE EXPENSIVE THAN AIR COOLING.
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PURPOSE OF COOLING SYSTYEM BETTER GET THIS IN OUR NOTES KEEP ENGINE AT MOST EFFICIENT OPPERATING TEMPERATURE –TOO COLD = WASTED ENERGY (BTU) –TOO HOT = LOSS OF LUBRICATION AIR COOLED IS NOT ACCURATE –DESIGNED TO OVERCOOL LIQUID COOLING IS DESIGNED TO GET THE ENGINE TO WARM UP QUICKLY YET NOT OVERHEAT
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HERE ARE THE COMPONENTS OF THE LIQUID COOLING SYSTEM.
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WHAT IS THE LIQUID? COOLANT IS MADE UP OF A MIXTURE OF WATER AND ANTIFREEZE COOLANT LETS GET THIS IN OUR NOTES
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DAY THREE
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LETS REVIEW ENERGY –ENERGY CONVERSION –TYPES OF ENERGY HEAT –WHAT IT IS AND HOW IT IS MEASURED –DIFFERENCES BETWEEN TEMP AND BTU WHY WE HAVE COOLING SYSTEMS AIR COOLING –TYPES –FINS, SHROUDS, AND FANS –MAINTENANCE
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FOUR PURPOSES OF USING ANTIFREEZE 1. LOWER FREEZING POINT OF WATER PURE WATER = 32F 25% ANTIFREEZE = 10F 50% ANTIFREEZE = -34F 68% ANTIFREEZE = -92F PURE ANTIFREEZE = -10F
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FOUR PURPOSES OF USING ANTIFREEZE 1. LOWER FREEZING POINT OF WATER 2. RAISE BOILING POINT OF WATER WATER BOILS AT 212F 25% ANTIFREEZE BOILS AT 218F 50% ANTIFREEZE BOILS AT 225F PURE ANTIFREEZE BOILS AT 320F
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FOUR PURPOSES OF USING ANTIFREEZE 1. LOWER FREEZING POINT OF WATER 2. RAISE BOILING POINT OF WATER 3. PREVENT RUST/CORROSION AND DEPOSITS IS AN ADDITIVE THAT EVENTUALLY NEEDS REPLACED
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RUST/CORROSION AND DEPOSIT SLOW DOWN THE HEAT TRANSFER ACTS AS A BLANKET
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FOUR PURPOSES OF USING ANTIFREEZE 1. LOWER FREEZING POINT OF WATER 2. RAISE BOILING POINT OF WATER 3. PREVENT RUST/CORROSION AND DEPOSITS IS AN ADDITIVE THAT EVENTUALLY NEEDS REPLACED 4. LUBRICATES WATER PUMP SEAL IS AN ADDITIVE THAT EVENTUALLY NEEDS REPLACED
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THERE ARE DIFFERENT KINDS OF COOLANT GREEN (CONVENTIONAL) –RECOMMENDED TO BE CHANGED ONCE A YEAR PINK (DEX COOL) –RECOMMENDED TO BE CHANGED EVERY 5 YEARS (SOME PROBLEMS) ORANGE
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DON’T MIX DIFFERENT KINDS DISPOSE OF PROPERLY SMELLS SWEET CHILDREN AND ANIMALS WILL DRINK IS TOXIC
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COMPONENTS LETS GET THESE IN OUR NOTES UNDER LIQUID COOLING WATER JACKETS –PASSAGES MADE (CAST) INTO CYLINDER BLOCKS AND HEADS –SPACES WHERE COOLANT FLOWS
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CAUSES COOLANT TO FLOW USUALLY DRIVEN BY BELT FROM CRANK SHAFT SUPPORTED BY BEARNING SEAL PREVENTS COOLANT LEAKAGE WATER PUMP WEEP HOLE TO PREVENT LEAKING COOLANT AWAY FROM BEARING
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OVER TIGHTING BELT WILL CAUSE BEARING FAILURE UNDER TIGHTING WILL CAUSE BELT SLIPAGE ENGINE OVER HEAT WILL RESULT BELT FAILURE WILL RESULT
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RADIATORS
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DAY FOUR
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LETS REVIEW AIR COOLING LIQUID COOLING –COOLANT PURPOSES OF ANTIFREEZE HOW TO HANDLE –WATER JACKETS –WATER PUMPS
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HAVE LARGE SURFACE AREA FOR HEAT TRANSFER. FINS ON RADIATOR ADD SURFACE AREA FOR HEAT TRANSFER. COOLANT USUALLY TRAVELS FROM TOP TO BOTTOM.
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PRESSURE CAPS SEALS COOLING SYSTEM TO ALLOW PRESSURE TO FORM FROM EXPANDING COOLANT PRESSURE RAISES BOILING POINT OF WATER 1 LB OF PRESSURE RAISES BOILING POINT 3 DEGRES F PREVENTS A VACUUM FROM FORMING AS COOLANT COOLS AFTER SHUT DOWN
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WARNING! WARNING! WARNING! NEVER REMOVE CAP FROM HOT RADIATOR
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PRESSURE CAP OPERATION SEALING, COOLANT HEATING AND EXPANDING CREATING PRESSURE PRESSURE EXCEEDES SPRING, VALVE OPENS AIR AND COOLANT LEAVE OVERFLOW TUBE AS COOLANT LOSSES TEMPERATURE IT CONTRACTS. A VACUUM IS PREVENTED SO RADIATOR AND HOSES WON’T COLLAPSE.
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ALLOWS COOLING SYSTEM TO REMAIN FULL AT ALL TIMES. PREVENTS CORROSION AND ALLOWS CHECKING OF COOLANT LEVEL WITHOUT REMOVING CAP. CAP FOR RECOVERY SYSTEM HAS TO HAVE TWO SEALS.
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THERMOSTAT OPERATION NOTE! WATER PUMP CIRCULATES ANYTIME ENGINE IS RUNNING
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ENGINE UP TO TEMPERATURE WAX PELLET EXPANDS PUSHING VALVE OPEN. VALVE OPEN, COOLANT CAN FLOW TO RADIATOR TO COOL.
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THERMOSTAT NOTES CLOSED = COOLANT TRAPED IN ENGINE, GETS HOT OPEN = COOLANT CAN FLOW TO RADIATOR TO COOL ALLOWS JUST THE RIGHT AMOUNT TO FLOW TO KEEP EVEN TEMPERATURE MOST MODERN VEHICLES CALL FOR 195 F. USED TO BE AS LOW AS 140 F. MORE HEAT = MORE POWER AND GAS MILAGE (BTU’s) STUCK CLOSED –ENGINE OVERHEATS STUCK OPEN –LESS POWER –LESS EFFIENCY (MPG) –CONTAMINATED OIL –MORE EMISSIONS –HEATER BLOWING COLD AIR
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DAY FIVE
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HEATER CORE HOW WE HEAT PASSENGER COMPARTMENT –CONTROLLING HEAT HEATER CONTROL VALVE BLEND DOOR –LEAKS –LOSS OF HEAT THERMOSTAT STUCK OPEN PLUGGED LOW COOLANT LEVEL / NO FLOW
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SOFT PLUGS ALSO CALLED –FREEZE PLUGS –EXPANSION PLUGS –SAND PLUGS –CORE PLUGS LEAKS CHANGING
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HOSES TYPES –PRE-FORMED –FLEX SPRINGS WHEN TO CHANGE –HARD –SOFT –BULGING –BEFORE THEY BREAK RECOMMENDED EVERY 6 YEARS
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FANS PURPOSE –PROVIDE AIR FLOW THRU RADIATOR AT LOW SPEEDS. NOT NEEDED AT HIGH SPEEDS TYPES –SOLID –ENERGY CONSERVING FLEX CLUTCH ELECTRIC
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ONE MORE TIME, COMPONENTS OF THE LIQUID COOLING SYSTEM.
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TOOLS HYDROMETER BELT TENSION GAUGE PRESSURE TESTER THERMOMETER Ph TEST STRIPS OR METER
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THAT’S ALL
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