Flashcards in Cooling System Deck (12):
Mechanical temp gauges use a _________ filled sensor that functions much like a thermometer .
Electrical gauges use a sensor known as a ________ which changes its ________ as temp changes .
A thermostats primary function is to allow _______ warm up of the engine.
2 thermistor , resistance
For Diesel engines 15 w 40 is widely used it is becoming more common to see _____ or ______ .
2007 and newer Diesel engines are equipped with a ________ . It is important that the correct oil is used.
Some filter assemblies have a _________ in the housing they must be inspected during an overhaul.
1)5 w 30 , 10 w 30
3 bypass valve
The oil cooler bypass valve should have a slight worn appearance and must have no signs of ____________ .
If the engine has had a major bearing failure the oil cooler will have _______ in it and should be replaced .
When the truck has been run under a hard load oil and coolant temps should be normally no more than ______ degrees apart .
Maximum oil pressure is controlled by an oil pressure _______ .
Oil pressure relief valve dumps excess oil pressure either to the ________ or the suction side of the ________ .
__________ valve opens when pressure drop across the filter is greater than specification .
1 relief valve
2 oil pan , oil pump
3 pressure differential
On a thermostat a _______ sensing element actuates a ________ that is attached to the ________ .
When the engine heats to operating temp the thermostats seal cylinder gates of the passage to the _______ and routes coolant to the _________ .
SCA stands for ________ .
1 heat , piston , seal cylinder
2 coolant pump , radiator
3 supplemental coolant additive
SCA recommendations by engine manufactures depend on whether ________ or _________ cylinder lines are used , and ______ used in the system as well as fluid dynamics _______ flow or _____ flow.
OEMS recommend SCA levels be tested ________ .
Coolants ph level determines the relative ________ or ______ of the coolant
1 wet , dry , materials , high , low
2 every oil change
3 acidity , alkalinity
Acids may form in engine coolants when exposed to ______ or corrosion of ________ and _________ metals.
High alkalinity reading indicates _________ corrosion .
Optimum ph levels normally fails between ________ and ________ .
High acidity readings ( below ______ on the ph scale )
1 combustion gases , ferrous , copper
3 7.5 , 11.0
Water pumps are inspected for leaks and ________ .
Water pump leaks can be caused by ________ of coolant additives as well as over concentration of _________ .
If a water pump is gear driven the _______ should be visually inspected for wear and __________ can be measured .
1 worn bearings
2 over concentration , antifreeze
3 drive gear , backlash
Once a cooling system cools down to a point where ________ pressure is about .25 psi higher than coolant pressure , a vacuum _______ in the cap unseats and coolant is forced by________ pressure from the _________ tank to the __________ . If the valve fails to open _________ are collapsed .
1 atmospheric , valve , atmospheric , surge , radiator , hoses
Engine cooling fan solenoid which is normally closed and when energized by the ECM supplies air to _________ the fan clutch
Some systems use a temp sensing bulb located in the water jacket known as __________ that opens or closes depending on temp .
Cold leaks occur due to _______ of sealing components .
2 fan thermostats
Silicon hoses require _______ hose clamps to keep constant pressure on hoses throughout the _______ and contraction .
The entire cooling system should be checked for white chalky ______ which are ________ left behind when coolant _______ .
If the vent fails to open the cooling system will enter a _______ as it cools and hoses will ________ .
1 constant torque , expansion
2 deposit , mineral deposits , leaks
3 vacuum , collapse