The 9U-7400 Multitach is used to measure the fan rpm. The
testing procedure is in Tool Operating Manual, NEHS0605.
Adding The Antifreeze
Do not add pure antifreeze to the cooling system in order to
adjust the concentration of antifreeze. The pure antifreeze
increases the concentration of antifreeze in the cooling system.
The increased concentration increases the concentration of
dissolved solids and undissolved chemical inhibitors in the
Add an antifreeze and water mixture in the concentration which
provides the desired freeze protection. Use the following chart
in order to determine the correct concentration of antifreeze in
water to use.
Antifreeze Concentration For Freeze Protection
and 70% water
and 60% water
and 50% water
and 40% water
Testing The Pressure Cap
One cause for a pressure loss in the cooling system can be a
defective seal on the radiator pressure cap.
9S-8140 Pressurizing Pump.
(1) Release valve
The 9S-8140 Pressurizing Pump pressurizes the cooling
system in order to test for leaks.
Pressure cap that is mounted on the radiator.
(4) Sealing surface between the pressure cap and the radiator.
Use the following procedures to inspect the pressure cap and
test the pressure cap:
Pressurized system: Hot coolant can cause serious bum.
To open cap, stop engine, wait until radiator is cool. Then
loosen cap slowly to relieve the pressure.
When the engine has cooled, loosen the pressure cap
to the first stop. Remove the pressure cap when the
pressure is released from the cooling system.
Inspect the pressure cap carefully. Look for damage to
the seal. Look for damage to the surface that seals.
Remove any debris on the cap, the seal, or the sealing