TRUCK SERVICE MANUAL
Record Oil Pressure
Screen Element Breather Cleaning
Start the engine and operate at 800 to 1000 rpm until the
oil temperature gauge reads 140 deg. F [60 deg. C].
1. Remove vent tube if not previously removed.
Reduce engine speed to idle and record the oil pressure.
A comparison of pressure at idling speed with previous
2. Remove capscrews, washers, cover screens and
readings will give an indication of progressive wear of
baffle from the breather body.
lubricating oil pump, bearings, shafts, etc.
readings are more accurate and reliable when taken
3. Clean vent tube, screens and baffle in an approved
immediately after an oil change.
cleaning solvent. Dry with compressed air. Wipe
out breather housing.
4. Assemble baffle, screens and new gasket in body.
5. Replace cover with cover boss resting securely on
1. Remove drain plug from bottom of filter case and
point of screen; secure with washers and capscrews.
6. Replace vent tube.
2. Loosen bolt at top of fuel filter. Take out dirty
element, clean filter case and install a new element.
3. Fill filter case with clean fuel to aid in faster pick-up
of fuel. Install a new gasket in filter head and
assemble case and element. Tighten center bolt to
20 to 25 ft-lbs [27 to 34 No m] with a torque wrench.
Check Air Piping Turbocharger
Check air intake piping from air cleaner to turbocharger
or intake manifold.
Check for loose clamps,
connections, cracks, punctures or tears in hose or
tubing. Tighten clamps,
manifold capscrews and
turbocharger mounting nuts.
Replace parts as
necessary to insure an air-tight intake system.
Check Inlet Air Restriction Gauge
The best method for determining dry-type air cleaner
maintenance periods is through air restriction checks.
A mechanical restriction gauge is available/to indicate
excessive air restriction. This gauge can be mounted in
air cleaner outlet or on vehicle instrument panel. The
restriction indicator signals when to change cartridges.
The red flag
in window gradually rises as
cartridge loads with dirt. Do not change cartridge until
Fig. 2-22, (N20311) Crankcase breather combination
flag reaches top and locks in position. When locked, flag
will remain up after engine is shut down. Change
cartridge when flag locks at top.
Check Throttle Linkage
cartridge, reset indicator by pushing reset button
Check throttle linkage and make sure it is in good
button all the way in firmly; then release. If button sticks,
operating condition. Check throttle travel to make sure
repeat pushing slowly.
linkage operates throttle from stop to full throttle.
Note: Never remove felt washer from gauge, it is
necessary to absorb moisture.
Change DCA Water Filter
Clean Air Cleaner Elements
Change filter or element at each "B" Check; selection of
Refer to Fuel System for instructions pertaining to
element to be used should be based upon size of
servicing the Air Cleaner.
system. See "Coolant .