3406E and 3456 Industrial Engines – Valve Covers

Remove & Install Valve Covers

Fluid Spillage Containment

Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to “Tools And Shop Products Guide”, NENG2500 for tools and supplies suitable to collect and contain fluids in Caterpillar machines. Dispose of fluids according to local regulations and mandates.

1. Remove bolts (1) that hold valve cover to (2) valve cover base. Remove valve cover (2).


Before removing the middle valve cover, loosen the clamps on breather cap (4) and remove it from the hose and valve cover.

2. Check the condition of the valve cover seal (3). If the valve cover seal appears to be worn or damaged, use a new part for replacement.

NOTE: The following steps are for installation of the valve cover.


For further information concerning the installation and tightening sequence for the valve cover base, refer to the Specifications Module.

3. Put valve cover (2) in position on the valve cover base. Install the bolts that hold the valve cover in place. Tighten the bolts to a torque of 18 ± 3 N·m (13 ± 2 lb ft).

4. Install breather cap (4) into the breather tube and valve cover. Tighten the two clamps. Connect the hose to the breather cap and tighten the two clamps.