GMC 1990 Light Truck Repair Manual page 4

To reduce the chance of personal injury and/or property damage, the following
instructions must be carefully observed.
Proper service and repair are important to the safety of the service technician
and the safe, reliable operation of all motor vehicles. If part replacement is
necessary, the part must be replaced with one of the same part number or with
an equivalent part. Do not use a replacement part of lesser quality.
The service procedures recommended and described in this service manual
are effective methods of performing service and repair. Some of these proce­
dures require the use of tools specially designed for the purpose.
Accordingly, anyone who intends to use a replacement part, service proce­
dure or tool, which is not recommended by the vehicle manufacturer, must first
determine that neither his safety nor the safe operation of the vehicle will be
jeopardized by the replacement part, service procedure or tool selected.
It is important to note that this manual contains various
Notices that must be carefully observed in order to reduce the risk of personal
injury during service or repair, or the possibility that improper service or repair
may damage the vehicle or render it unsafe. It is also important to understand
that these 'Cautions' and 'Notices' are not exhaustive, because it is impossible
to warn of all the possible hazardous consequences that might result from
failure to follow these instructions.
CAUTION
Cautions and