Rover DEFENDER 300Tdi, Workshop Manual

Page: 36 / 450

07
GENERAL FITTING REMINDERS
6 INFORMATION
FUEL SYSTEM HOSES
CAUTION: All fuel hoses are made up of
two laminations, an armoured rubber outer
sleeve and an inner viton core. If any of
the fuel system hoses have been disconnected, it
is imperative that the internal bore is inspected to
ensure that the viton lining has not become
separated from the amoured outer sleeve. A new
hose must be fitted if separation is evident.
METRIC BOLT IDENTIFICATION
1. An ISO metric bolt or screw, made of steel and
larger than 6 mm in diameter can be identified by
either of the symbols ISO M or M embossed or
indented on top of the head.
2. In addition to marks to identify the manufacture,
the head is also marked with symbols to indicate
the strength grade, e.g. 8.8, 12.9 or 14.9, where
the first figure gives the minimum tensile
strength of the bolt material in tens of kgf/mm
2
.
3. Zinc plated ISO metric bolts and nuts are
chromate passivated, a gold-bronze colour.
METRIC NUT IDENTIFICATION
1. A nut with an ISO metric thread is marked on
one face or on one of the flats of the hexagon
with the strength grade symbol 8, 12 or 14.
Some nuts with a strength 4, 5 or 6 are also
marked and some have the metric symbol M on
the flat opposite the strength grade marking.
2. A clock face system is used as an alternative
method of indicating the strength grade. The
external chamfers or a face of the nut is marked
in a position relative to the appropriate hour
mark on a clock face to indicate the strength
grade.
3. A dot is used to locate the 12 O’clock position
and a dash to indicate the strength grade. If the
grade is above 12, two dots identify the 12
O’clock position.
KEYS AND KEYWAYS
1. Remove burrs from edges of keyways with a fine
file and clean thoroughly before attempting to
refit key.
2. Clean and inspect key closely; keys are suitable
for refitting only if indistinguishable from new, as
any indentation may indicate the onset of wear.
TAB WASHERS
1. Fit new washers in all places where they are
used. Always fit a new tab washer.
2. Ensure that the new tab washer is of the same
design as that replaced.