1. COOLING AND COMFORT HEATING SYSTEMS
CHAPTER 3
Page 54 Classroom Manual
Page 56 Lab Manual
Chapter 35 & 36 Modern Automotive Technology

2. Pg... 44C
ENGINE HEAT
Normal operation produces heat that must be carried away by coolant
Accomplished by Conduction, Convection and Radiation
Coolant transfers heat to less hot outside air.
Coolant does not change state as with A/C

3. COOLING SYSTEM OPERATION
System design removes 35% of total heat
If not equipped with factory A/C, cooling system usually not able to handle additional heat load
Uses Radiator to transfer heat. Most radiators about sq. feet.

4. COMPONENTS 5 COOLING SYSTEM COMPONENTS Water Pump Cooling Fan Radiator
Pressure Cap
Thermostat

5. COMPONENTS

6. RADIATORS Two Types Pg. 47C PRESSURE CAPS Radiator Diagnosis
Vertical Flow Tubular Construction
Cross Flow Cellular Construction
PRESSURE CAPS
Equipped with Vacuum and Pressure Valve
Used to raise Pressure in system
Radiator Diagnosis
Radiator Repair
Pg C
Pg L

7. WATER PUMPS Centrifugal Type Water Pump
Pg C
Pg L
Centrifugal Type Water Pump
Inlet comes from bottom of Radiator
Outlet is through impeller to engine
Allows circulation when thermostat is closed
Water Pump Replacement is usually due to leaks
Transfer pump parts and use correct gaskets

8. PULLEYS AND BELTS Pitch and Width must be correct
Pg & 234C
PULLEYS AND BELTS
Pitch and Width must be correct
Tension belt in foot pounds
Serpentine Belts and Diagrams
Some water pumps turn in opposite direction

9. THERMOSTATS Senses coolant temperature and regulates temperature
Part of cooling system design
Temperature should not be changed
Stat will not cause overheating unless it is defective
Stat will not cause overcooling unless bad
Pg C
Pg L

10. COOLING FANS Engine driven fans
Pg C
Pg L
Engine driven fans
Fan Clutch - Speed limiting & Heat Sensing
Flexible Fans
Electric Fans - Can operate anytime
Fans are necessary for low speed operation
Can be Clockwise or CCW
Diagnosis and Inspection

11. Pg L
Pg C
HOSES AND CLAMPS
Made of oil and ozone resistant reinforced synthetic rubber
Performed or Molded Hoses
Flexible hoses
Worm gear type hose clamps
If one hose is bad, usually a good idea to replace all hoses

12. Pg L
Pg C
HOSES AND CLAMPS
Clamp Placement must be correct

13. ANTI-FREEZE AND ADDITIVES
Pg C
Pg L
Ethylene glycol based - Good for 1-2 yr
50/50% solution recommended
Lowers Freezing Point
Raises Boiling Point
Provides lubrication
Inhibits Rust and Corrosion
Protection Chart Pg L
Testing (Strength and Electrolysis)

14. PREVENTATIVE MAINTENANCE
Every 12K to 15K miles perform cooling system maintenance
Replace belts if bad
Replace antifreeze 50/50 mixture
Pressure Testing System
Check Fan operation

15. DIAGNOSIS Radiator Water Control Valve Water Pump Thermostat
Page L
DIAGNOSIS
Radiator
Water Control Valve
Water Pump
Thermostat
Cooling System Leaks
Electrical Related System

16. That’s All