B3U4 Cooling Systems And Engine Strating Aids Flashcards
(44 cards)
What happens to the thermostat when the coolant reaches operating temperature?
The thermostat opens allowing the hot coolant to move to the radiator.
What are the three common types of coolant hoses?
(1) Straight hoses.
(2) Wire-reinforced hose.
(3) Flex hose.
Regardless of the design, what three parts make up a radiator?
(1) Tanks.
(2) A core.
(3) A pressure cap.
What determines whether the fan is suction or blowing?
The pitch of the blade and the direction that the fan spins.
What is the common mixture you find as your coolant?
60 percent ethylene glycol to 40 percent water.
What types of fans might you find on an air-cooled engine?
Centrifugal or axial-flow type fan used.
Why does the coolant enter the lower portion of the water jacket pushing upward?
This ensures there is always coolant in contact with all internal engine components at all times.
At what pressure do most cooling systems operate?
10 to 15 psi
Where does the shroud direct the air on an air-cooled engine?
From the fan, across the cooling fins, and out away from the engine.
A 60 percent ethylene glycol to 40 percent water mixture raises the boiling point to what temperture?
Around 276 degrees F
Why are coolant additives necessary?
To prevent liner pitting, corrosion and scale build-up on your cooling system components.
What does scale in a cooling system cause?
Hot spots within the engine and clogs the tubes in the radiator core.
When is the hydrometer most accurate and easiest to read?
When you take the reading with the coolant near the normal operating temperature.
Once you have the fan and guards out of the way, what is the first step in removing the water pump?
Removing the coolant hoses.
What does removing the radiator cap before you drain the coolant do for you?
Prevent any vacuum hindering the coolant from draining.
For what do you inspect hoses?
Leaks at the connections, tightness of the hose clamps, cracks, dry rot, and pliability.
What are two ways tension is applied to belts?
(1) Spring loaded tensioning pulley.
(2) A pulley with a jacking bolt.
What are the two most common types of coolant heaters?
(1) Circulating.
(2) Immersion.
How do immersion coolant heaters spread heat throughout the engine?
By convection, so warm-up time is increased when compared to external coolant heaters.
Why is it important that you do not use starting fluid on engines that are equipped with glow plugs?
It can cause an explosion that can damage the engine and cause injury to you.
What is the only safe method of using ether?
(1) With a closed dispensing system.
What procedures are used when the operating temperatures are abnormally high?
(1)a closed dispensing system.
Adjust loose fan belts to their proper tension to prevent slippage.
(2) Check for improper size radiator or inadequate shrouding.
(3) Adjust, repair, or replace inoperative temperature-controlled fans.
(4) Check the coolant level, and fill the system to its proper level if low.
(5) Inspect for collapsed or disintegrated hoses, replace if faulty.
(6) If the thermostat is inoperative, remove, inspect, and test it. Replace the thermostat if you find it to be faulty.
(7) Check the water pump for loose or damaged impeller Inoperative thermostat, low coolant level and improperly sized or dirty radiator.
What is the most likely cause for abnormal low operating temperatures?
Faulty thermostat.
What type of situation causes the need to use a wire-reinforced hose in the cooling system to prevent the lower radiator hose collapse?
a. Low pressure from the engine.
b. Extreme heat from the radiator.
c. High suction from the water pump.
d. Excessive strain from the thermostat.
C. High suction form the water pump
