User Manual

48 SENR9977
Testing and Adjusting Section
Checking the Filler Cap
Onecauseforapressurelossinthecoolingsystem
can be a faulty seal on the radiator pressure cap.
g00296067
Illustration 54
Typical sche
matic of filler cap
(1) Sealing surface between the pressure cap and the r adiator
Personal injury can result from hot c oolant, 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 w ith your bare hand.
To check for the amount of pressure that opens the
filler cap, use the following procedure:
1. After the engine cools, carefully loosen the filler
cap. Slowly release the pressure from the cooling
system. Then, remove the filler cap.
2. 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 surface.
Carefully inspect the filler cap. Look for any
damage to the seals and to the sealing surface.
Inspect the following components for any foreign
substances:
•
Filler cap
•
Seal
•
Surface for seal
Remove any deposits that are found on these
items, and remo
ve any material that is found on
these items.
3. Install the pr
essure cap onto a suitable
pressurizing Pump.
4. Observe the ex
act pressure that opens the filler
cap.
5. Compare the pr
essure to th e pressure rating that
is found on the top of the filler cap.
6. If the filler
cap is damaged, replace the filler cap.
Testing The R
adiator And Cooling
System For Leaks
Use the following procedure to test the radiator and
the cooling system for leaks.
Personal in
jury can result from hot coolant, s team
and alkali.
At operatin
g temperature, engine coolant is hot
and under pressure. The radiator and all lines
to heaters o r the engine contain hot coolant or
steam. Any c
ontact 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.
1. When the en
gine has cooled, loosen the filler cap
to the first stop. Allow the pressure to release from
the cooling system. Then remove the filler cap.
2. Make sure that the coolant covers the top of the
radiator core.
3. Put a suitable pressurizing Pump onto the radiator.
4. Use the pre
ssurizing pump to increase the
pressure to an amount of 20 kPa (3 psi) more than
the operating pressure of the filler cap.
5. Check the radiator for leakage on the outside.
6. Check all
connections and hoses of the cooling
system for leaks.
The radia
tor and the cooling system do not have
leakage if all of the following conditions exist:
•
YoudoNOT
observe any leakage after five
minutes.