REMOVAL & INSTALLATION
8-420 (6.9L) and 8-444 (7.3L) Diesel
The diesel is the only engine covered in this guide which has removable valve seats.
- Using Ford Rotunda tool 14-0309, or equivalent, the exhaust valve seats may be removed. Position the remover collet into the insert and rotate the collet nut clockwise to expand the collet jaws under the lip of the seat insert.
- Rotate the top nut clockwise to remove the insert.
If an oversize seat insert is required, the cylinder head should be sent out to a qualified machine shop.
- To install a new exhaust valve seat, drive the seat in place using Rotunda tool 14-0309, or equivalent, and a hammer.
Valve seat inserts are supplied for service in standard size, 0.015 in. (0.381mm) oversize and 0.030 in. (0.762mm) oversize.