freightliner PE116DC, Maintenance Manual

Page: 41 / 164

20–00 Safety Precautions
Safety Precautions in this section apply to all
procedures within this group.
DANGER
When working on the vehicle, shut down the en-
gine or motor, set the parking brake, and chock
the tires. Before working under the vehicle, always
place jack stands under the frame rails to ensure
the vehicle cannot drop. Failure to follow these
steps could result in serious personal injury or
death.
20–01 Pressure Relief Cap
Check
WARNING
Do not remove or loosen the surge tank cap until
the engine and cooling system have completely
cooled. Use extreme care when removing the cap.
A sudden release of pressure from removing the
cap prior to the system cooling can result in a
surge of scalding coolant that could cause seri-
ous personal injury.
1. Remove the surge tank filler cap first, to relieve
the cooling system pressure, then remove the
SAE cap; see
Fig. 1 .
2. Using the Snap-On tool radiator-cap tester
shown in
Table 1 , check the pressure relief cap
to see if it maintains pressure to within 10% of
the pressure rating marked on the cap. If it does
not, replace the cap. Make sure that the replace-
ment cap is correctly rated for the cooling system
of the vehicle. Use the recommended tool in
Table 1 .
Tool Part Number
Radiator-Cap Tester TA53
Table 1, Snap-On Tool For Pressure Relief Cap Test
3. There is a second valve in the pressure relief
cap that opens under vacuum. This prevents the
collapse of hoses and other parts that are not
internally supported when the system cools. In-
spect the vacuum-relief valve to be sure it is not
stuck.
4. Make sure that the filler cap seals properly on
the coolant filler neck seat, and that the O-ring is
not cracked or deteriorated. Replace the cap if
the O-ring shows deterioration or damage.
20–02 Radiator Pressure-
Flushing and Coolant
Change
NOTE: For additional instructions on cleaning
and flushing the engine cooling system, see the
applicable engine manufacturer’s maintenance
and operation manual.
1. Apply the vehicle parking brakes, then chock the
tires. Tilt the hood.
2. Place a suitable container under the elbow of the
radiator outlet pipe and the radiator. The con-
tainer should hold at least 60 quarts (59 liters) of
fluid.
f200865 05/04/2016
1
2
3
1. Surge Tank Filler Cap
2. Surge Tank
3. Pressure Relieve Cap (for coolant overflow pressure
relief only)
Fig. 1, Surge Tank
Engine Cooling/Radiator
20
New Cascadia Maintenance Manual, November 2019
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