Tarleton State University 201 Agricultural Power Units Cooling Systems Department of Agricultural Services and Development

Cooling Systems Engines Chapter 8  What is cooling systems jobs?  1. Prevents _________  2. Regulates ________

Types of Cooling Systems  1. ________________ - uses air passing around engine to dissipate heat.  2. ________________ - uses a liquid to cool the engine and air to cool the liquid.

Small Engines What type cooling system is used on small engines? What is classified as a small engine?

Part of the Liquid Cooling System  Name the normal components of a liquid cooling system…  1. ___________________  2. ___________________  3. ___________________  4. ___________________  5. ___________________  6. ___________________  7. ___________________  8. ___________________

Radiators  What are the two types of radiators used in liquid cooling systems?  1. ________________  2. ________________  Does the radiator cool from the bottom up or from the top down? _____________________

Testing the Radiator  What should be checked with the tester in place? Radiator Water pump _____________ Drain cocks Cylinder block

Radiators continued  The radiator is pressurized to ____ to _____ psi.  The pressure system permits operating the engine at a higher temperature without boiling the coolant.

Radiator Cap  The two functions: 1. Allows atmospheric pressure to enter the cooling system. 2. Prevents coolant escape at normal pressures.

Fan and Fan Belts  What are the two types of fans?  ________________  The ideal location of the fan is approximately 2 ½ inches from the radiator core.

Water Pump  The water pump is normally a _________ type and might be called the “heart” of the cooling system.  Some pumps turn to _______ rpm and pump as much as _____ gpm.

Water Pump  Most pumps today have self-lubricated, sealed ______ bearings.  A typical water pump is made up of a… _________________

Engine Water Jacket  What make up the water jacket of an engine?  _________________  Engine water jackets hold only a small amount of water –  What are two advantages of this?  _____________________

Water Jacket Diagram

Coolant Filter  Some engines have coolant filters.  What are the two functions?  1. ________________  2. ________________

Thermostats  The thermostat provides automatic control of engine temperature at the correct level.  Some larger engines have _________ thermostats for temp. control.

Thermostats  What controls the opening and closing of a thermostat?  _________________  The actuator is filled with special wax and granular copper or bimetallic strips or a bellows tube filled with __________.

Types of Coolants  Low-boiling-point alcohol  Methanol  Ethylene glycol  Propylene glycol  Distilled water

Cooling Systems Hoses  Problems that occur…  _________________

Maintenance and Care  Rust proof the system  Keep at proper levels  Drain and replace according to the manufacturers specifications  Keep the radiator clean and straight

Other Stuff  What are freeze plugs/Welch plugs purpose?  __________________  What is sludge?  __________________  How do head gaskets affect cooling systems?  __________________  What is aeration?  __________________

Parts  Cup Plugs, also referred to as freeze plugs, drawn cups, cups or just plain plugs.

Head Gaskets

Parts

Hoses, Belts, and Radiator Cap

Intercooler for Turbo Engines

Water Pumps and Coolants

Testing and Changing the Coolant

Review  Write and answer five multiple choice questions covering any of today’s material.  Turn in when you are compiled your questions with ANSWERS.  Laboratory Inspection of Vehicles Fluid levels, belts, hoses, tire wear and pressure, inspection sticker, coolant rating, and air cleaner