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Cooling System
Cooling System Maintenance
At the intervals shown in the Maintenance Schedules
Section of the manual, the system should be drained,
flushed and filled.
Inspection
Check engine coolant (antifreeze) protection every 12
months (before the onset of freezing weather, where
applicable). If coolant is dirty or rusty in appearance, the
system should be drained, flushed and refilled with fresh
coolant as specified.
Inspect the entire cooling system for leaks. Check the face
of the radiator for any accumulation of bugs, leaves, or
other foreign matter. If dirty, clean the radiator core with
a garden hose. With the engine OFF, gently spray water
from the back of the radiator core.Check the coolant bottle hoses for condition and tight-
ness of the connections at both the coolant bottle and
radiator.
Check the coolant pressure cap and coolant reserve
system for proper vacuum sealing. With the engine at
normal operating temperature, note the level of the
coolant in the coolant bottle. Without removing the
pressure cap (with the engine off), drain a small amount
of coolant from the radiator draincock. If the coolant level
in the coolant bottle drops, the system is sealing properly.
Coolant Level
The coolant reserve system provides a quick visual
method of determining that the coolant level is adequate.
With the engine idling, and warmed to the normal
operating temperature, the level of the coolant in the
coolant bottle should be between the fluid level marks.
Check the coolant level whenever the hood is raised.
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The radiator normally remains completely full, so there is
no longer a need to remove the coolant pressure cap
except for checking coolant freeze point or replacement
with new antifreeze coolant.
WARNING!
Never add coolant to the radiator when the engine is
overheated. Do not loosen or remove pressure cap to
cool an overheated engine! The coolant is under
pressure and severe scalding could result.
Drain, Flush And Refill
At intervals shown on the Maintenance Schedules, the
system should be drained, flushed and refilled. Refer to
your dealer or consult a service manual for proper
procedures.
Adding Coolant
When adding coolant, or refilling the system, a minimum
solution of 50% recommended HOAT ethylene glycol
engine coolant (antifreeze) and distilled water should be
used. Use higher concentrations (not to exceed 70%) if
temperatures below34°F (37°C) are anticipated.
Use only high purity water such as distilled or deionized
water when mixing the water/engine coolant solution.
The use of lower quality water will reduce the amount of
corrosion protection in the engine cooling system.
NOTE:It is the owner’s responsibility to maintain the
proper level of protection against freezing according to
the temperatures occurring in the area where the vehicle
is operated.
NOTE:Mixing coolant types will decrease the life of the
engine coolant and will require more frequent coolant
changes.
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When additional coolant is needed to maintain the
proper level, add the recommended concentration of
antifreeze and water to the coolant bottle. Do not overfill.
NOTE:Failure to follow the antifreeze concentration
and replacement recommendations, or failure to use
antifreeze formulated to prevent corrosion of all cooling
system metals, may result in radiator plugging, overheat-
ing, or cooling system leaks such as in core hole plugs.WARNING!
Never add coolant to the radiator when the engine is
overheated. Do not loosen or remove pressure cap to
cool an overheated engine. The coolant is under
pressure and severe scalding could result.
Recommended Engine Coolant
Refer to Fluids, Lubricants and Genuine Parts for correct
fluid type.
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CAUTION!
•Mixing of coolants other than specified engine
coolant, may result in engine damage, and de-
crease corrosion protection. If a non-HOAT cool-
ant is introduced into the cooling system in an
emergency, it should be replaced with the speci-
fied coolant as soon as possible.
•Do not use plain water alone or alcohol base
engine coolant (antifreeze) products. Do not use
additional rust inhibitors or antirust products, as
they may not be compatible with the radiator
engine coolant and may plug the radiator.
•This vehicle has not been designed for use with
Propylene Glycol based coolants. Use of Propy-
lene Glycol based coolants is not recommended.
Disposal Of Used Engine Coolant
Used ethylene glycol based engine coolant is a regulated
substance requiring proper disposal. Check with your
local authorities to determine the disposal rules for your
community. Do not store ethylene glycol-based engine
coolant in open containers or allow it to remain in
puddles on the ground. Prevent ingestion by animals and
children. If ingested by a child, contact a physician
immediately. Clean up any ground spills immediately.
Coolant Pressure Cap
The coolant pressure cap must be fully tightened to
prevent the loss of coolant and to insure that the coolant
will return to the radiator from the coolant bottle. The
pressure cap should be inspected and cleaned if there is
any accumulation of foreign material on the sealing
surfaces.
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WARNING!
The warning words “DO NOT OPEN HOT” on the
radiator pressure cap are a safety precaution. Heat
causes pressure to build up in the cooling system. To
prevent scalding or injury, do not remove the pres-
sure cap.
Hoses And Vacuum/Vapor Harnesses
Inspect surfaces of hoses and nylon tubing for evidence
of heat and mechanical damage. Hard or soft spots,
brittle rubber, cracking, tears, cuts, abrasions, and exces-
sive swelling indicate deterioration of the rubber.
Pay particular attention to those hoses nearest to high
heat sources such as the exhaust manifold. Inspect hose
routing to be sure hoses do not come in contact with any
heat source or moving component which may cause heat
damage or mechanical wear.Insure nylon tubing in these areas has not melted or
collapsed.
Inspect all hose connections such as clamps and cou-
plings to make sure they are secure and no leaks are
present.
Components should be replaced immediately if there is
any evidence of wear or damage that could cause failure.
Brake System
Power Disc Brakes (front and rear)
Disc brakes do not require adjustment; however, several
hard stops during the break-in period are recommended
to seat the linings and wear off any foreign material.
Brake Master Cylinder
The fluid level of the master cylinder should be checked
when performing under the hood service, or immedi-
ately if the brake system warning lamp indicates system
failure.
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The brake master cylinder has a translucent plastic
reservoir. On the outboard side of the reservoir, there is a
“MAX” dot and an “MIN” dot. The fluid level must be
kept within these two dots. Do not add fluid above the
MAX mark, because leakage may occur at the cap.
With disc brakes the fluid level can be expected to fall as
the brake linings wear. However, an unexpected drop in
fluid level may be caused by a leak and a system check
should be conducted.
Refer to Fluids, Lubricants and Genuine Parts for the
correct Fluid type.
WARNING!
Use of a brake fluid that may have a lower initial
boiling point, or is unidentified as to specification,
may result in sudden brake failure during hard
prolonged braking. You could have an accident.
WARNING!
Overfilling the brake fluid reservoir can result in
spilling brake fluid on hot engine parts and the
brake fluid catching fire.
Use only brake fluid that has been in a tightly closed
container to avoid contamination from foreign matter or
moisture.
CAUTION!
Do not allow a petroleum-base fluid to contaminate
the brake fluid. Seal damage may result.
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Brake Hoses
Inspection should be performed whenever the brake
system is serviced or at intervals specified. Inspect hy-
draulic brake hoses for surface cracking, scuffing or worn
spots. If there is any evidence of cracking, scuffing, or
worn spots, the hose should be replaced immediately!
Eventual deterioration of the hose can take place with
possible burst failure.
Clutch Hydraulic System
The clutch hydraulic system is a sealed maintenance-free
system. In the event of leakage or other malfunction, the
system must be replaced.
Clutch Linkage
If the clutch pedal linkage begins to squeak or grunt, the
clutch pedal pivot bushings should be lubricated. Refer
to Fluids, Lubricants and Genuine Parts for the correct
lubricant type.
Rear Axle And 4x4 Front Driving Axle Fluid Level
Refer to Fluids, Lubricants and Genuine Parts for the
correct Fluid type. For normal service, periodic fluid level
checks are not required. When the vehicle is serviced for
other reasons the exterior surfaces of the axle assembly
should be inspected. If gear oil leakage is suspected
inspect the fluid level.
This inspection should be made with the vehicle in a level
position. The fluid level should be even with the bottom
of the fill hole for the Manufacturer’s C205F HD Front
Axles. The fluid level should be 5/8” (16 mm) below on
9 1/4” Manufacturer’s Rear Axles.
For all 2500 Model axles, the fluid level should be 1/4” ±
1/4” (6.4 mm ± 6.4 mm) below the fill hole on the 9.25”
Front and 3/4”± 1/4” (19 mm ± 6.4 mm) on 10.5” Rear
axles.
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Drain and Refill
Vehicles operated in normal service do not have regularly
scheduled oil changes. If fluid has become contaminated
with water or to provide the correct viscosity grade, drain
and refill.
Lubricant Selection
Refer to Fluids, Lubricants and Genuine Parts for correct
fluid type.
NOTE:The presence of water in the gear lubricant will
result in corrosion and possible failure of differential
components. Operation of the vehicle in water, as may be
encountered in some off-highway types of service, will
require draining and refilling the axle to avoid damage.
Limited-Slip Differentials
Power Wagon AxlesDO NOT REQUIREany limited slip
oil additive (friction modifiers).
Transfer Case
Fluid Level Check
This fluid level can be checked by removing the filler
plug. The fluid level should be to the bottom edge of the
filler plug hole with the vehicle in a level position.
Lubricant Selection
Refer to Fluids, Lubricants and Genuine Parts for correct
fluid type.
Front Drive Shaft
The front drive shaft contains a grease fitting which
should be serviced at every oil change (see maintenance
schedule A/B).
Manual Transmission
Fluid Level Check
This fluid level can be checked by removing the filler
plug. If the level of the lubricant is more than 1/4” (6.4
mm) below the bottom of the filler hole while the vehicle
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