Cooling System Testing, Maintenance, and Repair

Cooling System Testing, Maintenance, and Repair

After this lesson you will be able to:

• List Common Cooling System Problems and their symptoms

• Describe the most common causes of system leakage, overheating, and overcooling.

• Perform a combustion leak test and system pressure test.

• Check the major cooling system parts for proper operation

Cooling System Problem Diagnosis

• Can you describe the cooling system problem? (temp light on, overheating, coolant loss)

• When does the problem occur? (All the time, highway speeds, or when idling)

• How long has the problem been present?

• When was the last time the coolant was replaced?

• Have any repair been made?

• Have you noticed coolant leaks?

• Any unusal noises? (Grinding at the front of the engine, hissing)

Multiple Choice

After gathering all the information from the last slide what should be done next?

• Verify the concern

• Connect the scantool and pull codes

• Replace the most likely component

• Return the car to the customer

Cooling System On-Board Diagnostics (OBD)

• OBD Systems can monitor the following...

• Coolant Temp

• Coolant Level

• Belt Tension

• Performance out of range

• Other related functions

Inspecting the Cooling System...

• A visual inspection will often reveal the source of a cooling system concern.

• Coolant Leaks

• Loose or Missing Belts

• Low Coolant

• Pump Noises

• Radiator Blockage

• Coolant in the oil

Multiple Select

Select the three major cooling system problems.

• Coolant Leaks

• Overheating

• Overcooling

• Coolant Explosions

• Over expansion

Cooling System Faults can be grouped into three categories.

• Coolant Leaks

• Overheating

• Overcooling

Cooling System Leaks

• Appear as wet, discolored areas around the engine

• Smell like coolant (sweet)

• Should be the same color as the coolant

Multiple Select

Select all of the following that could indicate a cooling system leak...

• Green Liquid dripping from the upper radiator hose

• Low coolant level in the overflow tank

• Engine will not reach operating temperature

• The electric cooling fan never runs

Keep in mind...

• If there is no sign of external coolant leak, then the leak may be internal to the engine.

• Cracked Block

• Cracked Cylinder Head

• Blown Head Gasket

How to find hard to identify cooling system leaks...

• Cooling System Pressure Test

• Low air pressure is forced into the cooling system to simulate cooling system pressure

• Most common cooling system leak detection tool

• Adds around 14PSI to the cooling system.

• When pressure is on the system, inspect the system for leaks

Cooling System Pressure Test Video

• Canvas Under Day 21: Cooling System Pressure Test Video

• Complete then you can leave the morning session.

• See you in the afternoon.