Detroit Diesel 4000 Series, Service Manual, Page: 1602 / 2706

SERIES 4000 12/16V SERVICE MANUAL
C 206.05.08 M – INSPECTION AND REPAIR
Perform the following steps to inspect and repair the thermostat housing:
1. Clean all parts with cold cleaner.
2. Visually inspect components for damage and defects.
[a] If damage or defects are detected, replace components as necessary.
[b] If no damage or defects are detected, continue inspection.
3. Using the surface crack-testing method with red penetrant dye, visually inspect the coolant
distribution housing and thermostat housing for cracks.
[a] If cracks are detected, replace component.
[b] If no cracks are detected, continue inspection.
To avoid an eye injury when blow drying parts, wear
adequate eye protection (safety glasses or faceplate) and
do not exceed 276 kPa (40 lb/in.
2
) air pressure.
4. If necessary, pressure test the coolant and oil chambers of the coolant distribution
housing with air in water bath (with corrosion inhibitor) for leaks (except cooling system
to cooling system).
NOTE:
Test Pressure: 0.5 bar
[a] If bubbles emerge, replace component as necessary.
[b] If bubbles do not emerge, continue inspection.
5. Visually inspect all mating surfaces for wear and damage.
[a] If wear or damage is detected, rub down with oilstone or emery cloth.
[b] If wear and damage are beyond repair, replace component as necessary.
[c] If no damage or wear is detected, continue inspection.
6. Visually inspect condition of thread in coolant distribution housing.
[a] If thread is worn or damaged, rechase threads as necessary.
[b] If thread is not worn or damaged, continue inspection.
7. Replace hose and clamps as part of every W6 overhaul.
8. Replace gaskets, sealing rings and O-rings.
All information subject to change without notice.
C -1456
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