REMOVAL & INSTALLATION
See Figure 1
If the valve seat is damaged or burnt and cannot be serviced by refacing, it may be possible to have the seat machined and an insert installed. Consult an automotive machine shop for their advice. Diesel engine valve seats can be ground only once. If the seat has been reground, service seats must be installed. One X stamped into the head identifies that the seats have been refaced. If the wall stamp is XX, it means service has been installed. Service seats can be reground. If you remove more than 0.010 in. (0.254mm) from the cylinder head combustion surface, install service seats. Measure the head height to determine if service seats are necessary. Check the rear lower right corner of the head for a stamping that would indicate previous resurfacing. The valve depth limit is 0.010 in. (0.254mm).