If the inner and outer caliper halves are incorrectly matched*, the internal porting will be screwed up. The result is that the outer-upper cylinder cannot be properly bled. Therefore that cylinder applies little or no braking pressure on the upper half of the outer pads.

I'm not positive that mis-match would cause your pad wear problem, but it's fairly easy to spot, and is a known problem with shoddily rebuilt Girling calipers.

* The Girling factory punch-marks a dimple on the bottom of each half, close to the mating line. If you see a punch mark on the TOP of an outer caliper half, it means the rebuilder didn't reassemble the halves correctly, and that half belongs (inverted) on the other side of the car.

EDIT: Note that just ONE mismatched front caliper will prevent proper bleeding of the upper cylinder on BOTH front calipers as well as the Left Rear caliper, since all 3 make up one half of the dual-diagonal hydraulic circuit on non-ABS 240s.


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Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.