Often used scrap of wood to catch pistons. Compressed air is applied to line connections.

This caliper is a non-vented Girling being replaced by calipers for vented rotors.

Both pistons rarely come free at once. This is a seal to place on the already cleared cylinder.

Seal made from fender washer and a bit of tire patch.

Removing the second piston.

Split caliper reveals washers and recess for them.

Note elliptical shape of drilled passage openings at machined surface.

Washers are resting on the flat surface, no counterbore is made on the inboard half.

Some rust can be seen near the right-most bolt hole.

Comparing washer to counterbore.

Looks like about 13 thousandths of compression occurs.

Inboard mating surface of non-vented at upper left, vented at lower right.

Yes, the left casting has an L.

Disassembling the right side caliper.

The right side casting does not have an “L”.

Outboards compared. Right at top.

After wire brush and a bit of yet-wet Krylon flat black, the punch marks are obvious.

We think these marks are meant to help keep the correct halves from getting mixed.

Tracing the drillings.

Looking in this bore with the straw passed in from the bleed screw opening. Depending on use as a right or left, this bore finds the bleed screw bore from this pot or the one shown above. Beside the ID stampings, the castings are otherwise the same.

Same shot better lighting.

Fluid in just below bleed bore.