General Fitting Instructions
In Fig. 1 and Fig. 2, this page,’K indicates the metric
type and ’B’ the UNF type.
Hose ends differ slightly between metric and UNF (Fig.
1). Gaskets are not used with metric hoses; the metric hose fit- ting seals against the bottom of the port and consequently
there is a gap between the hexagonal face of the hose fitting
and the cylinder (Fig.
2A). The UNF hose fitting is sealed on
the brakecylinder or caliperface by a copper gasket (Fig.
2B).
Pipe sizes (outside diameter) for UNF are 3/16 in., 1/4 in. and
5/16 in. Metric pipe sizes are 4,75 mm, 6 mm and 8 mm. The 4,75 mm pipe is exactly the same diameter as 3/16 in. pipe.
The 6 mm pipe is 0.014 in. smaller than 1/4 in. pipe. The 8
mm pipe is 0.002 in. larger than 5/16 in. pipe.
Convex flares for metric brake pipes have a different form
thanthoseon UNF brake pipes. When making pipesfor met
- ric equipment, metric pipe flaring tools must be used.
The greatest danger lies with the confusion of
10 mm and 3/8 in. UNF pipe nuts used for 3/16 in. (or 4,75 mm) pipe. The 318 in. UNF pipe nut or hose can be screwed into a 10 mm port, but is very slack and easily stripped. The thread en- gagement is very weak and cannot provide an adequate
seal. The opposite condition, a 10 mm nut in a 318 in. port,
will cause difficulty during fitting. The
10 mm nut will screw
in for one or two turns and then seize. It has a crossed thread
‘feel’ and
it is impossible to force the nut far enough to seal
the pipe. With female pipe nutsthe position is reversed. The
other combinations are so different that there is no danger
of confusion.
A3.2.12 Keys And Keyways
Remove burrs from the edges of keyways with a fine file and
clean thoroughly before attempting to refit the key. Clean
and inspect the key closely. Keys are suitable for refitting
only
if no indentations exist (which would indicate the onset
of wear).
A3.2.13 Split Pins
Fit new split pins throughout when replacing any unit. Al- ways fit split pins where split pins were originally used. Do not substitute spring washers for split pins. All split pins
should be fitted as shown (Fig. 3) unless otherwise stated.
A3.2.14 Tab Washers
Fit new tab washers in all places where they where used
originally. Never refit a used tab washer. Ensure that the
new tab washer is of the same design as that which was re
- moved.
A3.2.15 Special Fixing
Bolts with a blue coating applied to the thread are used in various areas ofthevehicle. Should any of these bolts be re- moved, they MUST be replaced with NEW bolts of the same
type. Nyloc nuts are used in various areas of the vehicle. If removed these MUST be replaced with NEW nuts of the
same type.
-A
507 008
Fia. 1
Fia. 2
Fig. 3 I
X300 VSM Issue 1 August 1994 6
General Fitting Instructions
I
Fault
Roller wear.
Cause
Marks on track and rollers caused by fine abrasives.
Remedy
Clean all components and housings. Check the seals and
bearings, and renew if leaking, rough or noisy.
Fault
Cracked race.
Cause
Race cracked due to incorrect fitting to shaft, tipping or poor
seating.
Remedy
Renew the bearing and check the condition of the seals.
Fault
Discolouration.
Cause
Discolouration ranging from black to light brown caused by
moisture or incorrect use of lubricants.
Remedy
Reuse bearings if stains can be removed by light polishing
or if no evidence of overheating is apparent. Checkthe seals
and other component part condition. Renew as necessary.
51 060
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1
Fault
Discolouration.
Cause
Heat discolouration ranging from blue to faint yellow,
resulting from overload or incorrect lubricant. As excessive
heat can cause softening of tracks and rollers, check by
drawing a fine
file over a softened area. If faulty, the file will
grab and cut metal. If still hard, the file will skid over the
surface without removing any material.
Remedy
Renewthe bearings and seals if any heat damage is evident.
51 062
Issue 1 August 1994 X300 VSM 10
