TM 5-3895-346-14
CYLINDER HEAD
ENGINE OVERHAUL
Fluorescent Penetrant Method: A highly fluorescent liquid penetrant is applied to the area in question. Then
the excess penetrant is removed from the surface and the part is dried. A developing powder is then applied
which helps to draw the penetrant out of the flaws by capillary action. Inspection to find the crack is carried out
using a black light.
Nonfluorescent Penetrant Method: The test area being inspected is sprayed with Spot-check or Dye Check.
Allow 1 to 30 minutes to dry. Remove the excess surface penetrant with clean cloths premoistened with
cleaner/ remover. DO NOT flush surface with cleaner/remover because this will impair sensitivity. Repeat this
procedure with additional wipings until residual surface penetrant has been removed. Shake developer
thoroughly until agitator rattles. Invert spray can and spray short bursts to clear valve. Then spray this
developer film evenly over the test area being inspected. Allow developer film to dry completely before
inspecting. Recommended developing time is 5 to 15 minutes.
NOTE
The above four methods provide basic instructions. Specific details should be
obtained from the supplier of the equipment or material.
Pressure Check Method: Pressure check the cylinder head as follows:
a.
Seal off the water holes in the head with steel plates and suitable rubber gaskets secured in
place with bolts and washers. Drill and tap one of the cover plates for an air hose connection.
b.
Install scrap or dummy injectors to ensure proper seating of the injector tubes. Dummy
injectors may be made from old injector nuts and bodies the injector spray tips are not necessary. Tighten the
injector clamp bolts to 20-25 lb ft (27-34 Nm) torque.
c.
Apply 40 psi (276 kPa) air pressure to the water jacket. Then immerse the cylinder head in a
tank of water, previously heating to 180-200 or 82-930 C, for about 20 minutes to thoroughly heat the head.
F
Observe the water in the tank for bubbles, which indicate a leak or crack. Check for leaks at the top and
bottom of the injector tubes, oil gallery, exhaust ports, fuel manifolds, and the top or bottom of the cylinder
head.
d.
Relieve the air pressure and remove the cylinder head from the water tank. Then remove
the plates, gaskets, and injectors and dry the head with compressed air.
e.
If the pressure check revealed any cracks, install a new cylinder head.
2. Check the bottom (fire deck) of the cylinder head for flatness as follows:
a.
Use a heavy, accurate straightedge and feeler gages, tool J 3172, to check for transverse
warpage at each end and between all cylinders. Also check for longitudinal warpage in six places as shown in
Fig. 3. Refer to Table 1 for maximum allowable warpage.
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