Thermo King UT-1200, Manual

Page: 90 / 169

Engine Maintenance
90
Oil Filter Change
The oil filters should be changed along with the
engine oil. Use genuine Thermo King extended
maintenance oil filters.
1. Remove the filter.
2. Apply oil to rubber ring of new filter and
install filter.
3. Tighten the filter until the rubber ring makes
contact, then tighten 1/2 turn more.
4. Start the unit and check for leaks.
Crankcase Breather System
The crankcase breather system ducts crankcase
gases formed in the crankcase directly to the air
intake. Harmful vapors that would otherwise
collect in the crankcase and contaminate the oil,
or escape to the outside, are drawn back into the
engine and burned.
The crankcase breather is located in the cylinder
head cover, which is a combination of valve cover
and intake manifold. A restrictor in the cylinder
head cover limits the flow of gases from the
crankcase to the intake and keeps the crankcase
pressure from getting too low.
Normal crankcase pressures with a new air
cleaner are shown below:
The vacuum will increase as the air cleaner gets
dirty and becomes more restrictive. Remove the
breather cover and the baffle plate and check to
make sure nothing is plugged or damaged.
See the TK270, TK370, and TK376 Engine
Overhaul Manual (TK 53163) for the procedure to
check the crankcase pressure. If your readings are
significantly more positive than 0 to 11 in. (0 to
279 mm) H
2
O of vacuum, you may have excess
blowby past the rings. A compression check
should be performed to confirm this.
The following items can effect the crankcase
pressure readings.
1. Spin-on Oil Filter
2. Bypass Valve Nut
3. Bypass Valve
Figure 158: Oil Filter Parts
Unit/Speed in. (mm) H
2
O of vacuum
Truck/Low 0 to 8 in. (0 to 203 mm)
Truck/High 2 to 11 in. (51 to 279 mm)
TriPac 0 to 8 in. (0 to 203 mm)
1. Breather Cover
2. O-ring
3. Baffle
4. Baffle Plate
Figure 159: Crankcase Breather Components
Crankcase
Pressure
Effect
Typical Cause
Increase Piston Rings Stuck or Worn
Increase Restrictor Plugged
Decrease Air Cleaner Dirty or Plugged
1
2
4
3