200 TROUBLESHOOTING

CYLINDER HEAD OIL PASSAGE LEAK CHECK — OUT OF CHASSIS

Refer to Figure 9-5.

1.Remove cylinder head from the engine.

2.Install a suitable plug to seal the rocker arm oil passage at deck side of head. There are two ways to plug the hole:

Drill and tap the oil passage to accept a pipe plug.

Insert a suitable rubber plug and clamp the plug in position with a C-clamp.

3.Install an air fitting in the rocker arm passage in the top of the head. Use a discarded rocker arm bracket, preferably with an oil feed passage. Cut the bracket through the rocker arm shaft bore parallel to the mounting surface. Drill and tap the oil supply passage to accept an air fitting.

4.Bolt the modified bracket, with air fitting, to the cylinder head over the oil supply passage.

5.Immerse cylinder head in water and heat to 150°F (66°C).

6.Apply up to 50 psi (345 kPa) air pressure to air fitting adapter installed in rocker arm oil passage. Check for air bubbles. The formation of air bubbles indicates internal leakage in cylinder head oil passage.

Do not exceed 50 psi (345 kPa). Damage to seals or cup plugs may result.