Cooling System Flashcards Preview

ASE diesel engines > Cooling System > Flashcards

Flashcards in Cooling System Deck (12):
1

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.

1 liquid
2 thermistor , resistance
3 rapid

2

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
2 Dpf
3 bypass valve

3

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 .

1 scoring
2 metal
3 25

4

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

5

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

6

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

7

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
2 aluminum
3 7.5 , 11.0
4 7.5

8

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

9

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

10

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 .

1 disengage
2 fan thermostats
3 contractions

11

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

12

Trucks have fans that are computer controlled and may be turned on by the engine _______ the _________ or ________ .

When examining fan controls verify the operation of computer input sensors such as the ______ sensor and the _______ .

The engine cooling fan manual switch is normally open , when closed request that the ECM turn off the engine cooling fan _______ . Causing the fan to operate continuously .

1 ECM , a/c , engine brake
2 ect , eot
3 solenoid