John F Sandhoff wrote:
> Paul asks:
> > After removing my front brake calipers I noticed a thin large washer on
> > the floor. Where did it come from?
>
> I've found there to be a paper-thin washer between the caliper assembly
> and the mounting point on the front axle assembly. There should have
> been a total of two - one for each of the two mounting points. It's
> quite likely that one stuck to either the axle or caliper and you didn't
> notice it, the other one fell off and you luckily noticed.
>
> I don't know what their exact purpose is, but I figure that Nissan
> stuck them in there for a reason :-)
>
I've held off writing in about this because I haven't got any hard facts for
the Datsun, but our calipers are the same as fitted to the early Jensen
Interceptors. The reason for the shims is to pack the caliper mounting points
so that the pads and pistons are dead square with the disc. Because of
manufacturing tolerances, there will not necessarily be the same number of
shims on both points. A secondary use is to ensure that the caliper is
mounted equidistant on both sides of the disc. Now, my workshop manual for
the early Interceptor doesn't give any figures but shows that a gauge is used
to set up the shims. When the calipers (for the Interceptor) were changed
from Dunlop to Girling, the manual then provides figures for shimming. I see
no reason why these figures can't be used for the Dunlop calipers, they work
just the same....
Basically it says that, measured from the pad abutments to the disc at either
end of the caliper, there should be no difference between gaps. On either
side of the disc (inner and outer caliper halves) there can be a difference
of .010". From memory, the gap between the pad abutments and the disc is on
the order of 1/2" so I use a length of lathe tool steel to fill most of the
gap and feeler gauges for the remainder but a large drill end would serve the
same purpose.
Brian Hampton
Adelaide
South Australia
'68 2000
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