3H6-04028-0 Nissan GAACKET

Visual Inspection Of The Cooling System
Cooling systems that are not regularly inspected are the cause for increased engine temperatures. Make a visual inspection of the cooling system before a test is made with test equipment.
Personal injury can result from escaping fluid under pressure.If a pressure indication is shown on the indicator, push the release valve in order to relieve pressure before removing any hose from the radiator.
Check the coolant level in the cooling system.
Look for leaks in the system.
Make sure that air flow through the radiator does not have a restriction. Look for bent core fins between the folded cores of the radiator. Also, look for trash between the folded cores of the radiator.
Inspect the drive belts for the fan.
Check for damage to the fan blades.
Look for air or combustion gas in the cooling system.
Inspect the filler cap, and check the surface that seals the filler cap. This surface must be clean. Testing The Cooling System
Illustration 1 g00286266
Boiling point of water
Remember that temperature and pressure work together. When a diagnosis is made of a cooling system problem, temperature and pressure must be checked. Cooling system pressure will have an effect on the cooling system temperature. For an example, refer to the Illustration 1. This will show the effect of pressure on the boiling point (steam) of water. This will also show the effect of height above sea level. Test Tools For Cooling System
Table 1
Tools Needed Quantity
4C-6500 Digital Thermometer 1
8T-2700 Blowby/Air Flow Indicator Group 1
9S-8140 Pressurizing Pump 1
6V-3121 Multitach 1
Making contact with a running engine can cause burns from hot parts and can cause injury from rotating parts.When working on an engine that is running, avoid contact with hot parts and rotating parts.
Illustration 2 g00300241
4C-6500 Digital Thermometer
The 4C-6500 Digital Thermometer is used in the diagnosis of overheating problems or in the diagnosis of overcooling problems. This group can be used to check temperatures in several different parts of the cooling system. Refer to the testing procedure in Operation and Maintenance Manual, SEBU6945.
Illustration 3 g00286269
8T-2700 Blowby/Air Flow Indicator Group
The 8T-2700 Blowby/Air Flow Indicator Group is used to check the air flow through the radiator core. Refer to the testing procedure in Special Instruction, SEHS8712.
Illustration 4 g00300249
9U-7400 Multitach
The 9U-7400 Multitach is used to check the fan speed. Refer to the testing procedure in Special Instruction, SEHS7807.Checking the Filler Cap
Illustration 5 g00286369
9S-8140 Pressurizing Pump
The 9S-8140 Pressurizing Pump is used to test the filler caps. This pressurizing pump is also used to pressure test the cooling system for leaks.
Personal injury can result from hot coolant, steam and alkali.At operating temperature, engine coolant is hot and under pressure. The radiator and all lines to heaters or the engine contain hot coolant or steam. Any contact can cause severe burns.Remove filler cap slowly to relieve pressure only when engine is stopped and radiator cap is cool enough to touch with your bare hand.Cooling System Conditioner contains alkali. Avoid contact with skin and eyes.
One cause for a pressure loss in the cooling system can be a defective seal on the radiator filler cap.
Table 2