If troubleshooting an internal coolant leak or coolant loss symptom, a cylinder head test fixture can be fabricated
from a flat piece of steel or aluminum to pressure test the cylinder head.
See the following table for test fixture dimensions.
NOTE: Use the old cylinder head gasket as a pattern for drilling the capscrew holes.
Install the thermostat, water outlet connection and mounting capscrews.
Tighten the capscrews
Torque Value: 10 Nā¢m [ 89 in-lb 1
Install the engine coolant temperature sensor, located next to the water outlet connection.
Torque Value: 18 Nā¢m [ 159 in-lb]
NOTE: The thermostat contains two check balls to vent air past the thermostat when closed. Install a rubber cap
and hose clamp over the water outlet connection to prevent air from leaking through the check balls.
Install the cylinder head water test fixture.
ā¢ Install a new head gasket.
ā¢ Install the test plate.
ā¢ Install the following:
ā¢ 26 – 180-mm-long grade 12.9 flange head capscrews
ā¢ 26- M12 x 1.75 hex flange nuts
ā¢ 52 – 12-mm washers
NOTE: Place a washer between each capscrew and the head, and between each nut and test plate. This will
prevent mutilation on the surface of the cylinder head.
Tighten the nuts in the sequence illustrated.
Torque Value: 80 Nā¢m [59 ft-lb]
Service Tip: To apply air pressure to the cylinder head, remove one of the pipe plugs located on the exhaust side
of the cylinder head. This is the same port used, when the cylinder head is installed, to check cylinder block coolant
pressures.
NOTE: Make sure to plug or seal any open coolant ports before pressure testing the cylinder head.
Connect a regulated air supply hose, Part Number 3164231, to the cylinder head.
Apply air pressure.
Air Pressure: 276 kPa [ 40 psi ]
Use a nylon lifting strap and a hoist to place the cylinder head in a tank of heated water.
Water Temperature: 60 Ā°C [ 140 Ā°F]
NOTE: The cylinder head must be completely submerged in the water.
Inspect the head. Bubbles indicate an air leak.
If any bubbles exist, verify the air leak is not coming from:
– Any cup plugs or fittings installed in the cylinder head
– Test fixture or air line fittings
– Water outlet connection.
If the above checks out OK and bubbles are present, the cylinder head leaks and it must be replaced.
Remove the test fixture.
Use compressed air to dry the cylinder head.
