0324565 JOHNSON SCREW

Illustration 1 g00921815
Boiling point of waterRemember 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 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.
Personal injury can result from hot coolant, steam and alkali.At operating temperature, engine coolant is hot and under pressure. The heat exchanger and all lines to heaters or the engine contain hot coolant or steam. Any contact can cause severe burns.Remove the filler cap slowly to relieve pressure only when the engine is stopped and the filler cap for the heat exchanger is cool enough to touch with your bare hand.Cooling System Conditioner contains alkali. Avoid contact with skin and eyes.
The coolant level must be to the correct level in order to check the coolant system. The engine must be cold and the engine must not be running. After the engine is cool, loosen the pressure cap in order to relieve the pressure out of the cooling system. Then remove the pressure cap.The level of the coolant should not be more than 13 mm ( 0.5 inch) from the bottom of the filler pipe. If the cooling system is equipped with a sight glass, the coolant should be to the proper level in the sight glass.Test Tools For Cooling System
Table 1
Tools Needed    
Part Number     Part Name     Quantity    
4C-6500     Digital Thermometer     1    
9S-8140     Pressurizing Pump     1    
9U-7400
or
1U-6602     Multitach Tool Group
or
Photo-Tachometer     1    
1U-7297     Coolant/Battery Tester     1    
1U-7298     Coolant/Battery Tester     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 g00876179
4C-6500 Digital Thermometer The 4C-6500 Digital Thermometer is used in the diagnosis of overheating conditions and in the diagnosis of overcooling conditions. This group can be used to check temperatures in several different parts of the cooling system. Refer to Operating Manual, NEHS0554, " 4C-6500 Digital Thermometer Group" for the testing procedure.
Illustration 3 g00286276
9U-7400 Multitach Tool Group The 9U-7400 Multitach Tool Group is used to check the fan speed. Refer to Operating Manual, NEHS0605, " 9U-7400 Multitach Tool Group " for the testing procedure.The 9U-7400 Multitach Tool Group can measure engine rpm from a magnetic pickup. This magnetic pickup is located in the flywheel housing. The magnetic pickup also uses the ability to measure engine rpm from visual engine parts that are rotating.
Illustration 4 g00296064
1U-6602 Photo-Tachometer The 1U-6602 Photo-Tachometer is a photo-tachometer that is held by hand for general use. The 1U-6602 Photo-Tachometer is a phototach, so this tachometer only registers basic input frequency on any visible, rotating part. The basic input frequency equals one revolution per a piece of reflective tape. The 1U-6602 Photo-Tachometer does not replace the 9U-7400 Multitach Tool Group.
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.
Illustration 6 g00439083
1U-7297 Coolant/Battery Tester or 1U-7298 Coolant/Battery Tester Check the coolant frequently in cold weather for the proper glycol concentration. Use either the 1U-7297 Coolant/Battery Tester or the 1U-7298 Coolant/Battery Tester in order to ensure adequate freeze protection. The testers are identical except for the temperature scale. The testers give immediate, accur