REPAIR INSTRUCTIONS

Valve Stem Seals

Refer to Figure 204.

The valve stem seal for the M-E7 engine uses a steel retainer band around the top of the seal lip.

To improve seal-to-guide retention, the valve guides have three sharp ridges machined into the upper outside diameter surface (refer to Figure 204). 204

Refer to Figure 205.

1.With valve spring keepers (1) removed, remove upper washer (2), valve spring (3), oil seal (4), lower washer (Roto-Coil) (5) and valve (6).

After removing the valve springs, removal of the existing valve stem seals can be accomplished easily and quickly by using the J 39460 Valve Stem Seal Removal tool. Failure to use this tool can make seal removal difficult, and also can result in damage to the outside diameter of the valve guides.

Repair Instructions

Fire Ring Groove

Description

Fire ring grooves are located in the machined flat surface of the cylinder head that mates with the engine block. These grooves correspond with the fire ring machined lip on cylinder liner. This design provides a locking groove for the fire ring to seat as well as a positive-combustion pressure seal.

After resurfacing the cylinder head deck, it is necessary to reestablish the fire ring groove depth using fire ring groove cutter J 29600-C. 206

Cylinder Head Inspection

Pressure Test It is recommended that cylinder heads be pressurized and checked for internal cracks and leaks. Refer to Cylinder Head and Cylinder Block Leak Test procedures in the Troubleshooting section.

Check cylinder head deck surface for warping, pitting or other imperfections. Deck surface flatness for a new head must not vary more than 0.0035 inch (0.0889 mm). Resurface or replace as necessary.

When resurfacing, remove a minimum amount of material from deck to obtain a flat, uniform surface. Standard head height is 6.397–6.391 inches (162.483–162.310 mm). A maximum of 0.010 inch (0.254 mm) of material may be removed, making the minimum height of a resurfaced head 6.381 inches (162.077 mm).

When the deck is resurfaced, fire ring groove and valve seat insert dimensions must be reestablished. Correct dimensions are shown in this section.