Disassembly

Remove the master cylinder from the vehicle; "2 nuts and 2 brake lines".

Remove the two clips that secure the cover.

Two clips folded back and cover removed.

Empty master cylinder. Clean out old “gunk” from inside.

Some masters have a small screw on the bottom, Bendix; remove it as shown by the arrow. 

Locate the clip at the back of the master cylinder.

Locate the clip at the back of the master cylinder.  You may need to depress the piston, it is under light spring pressure.

Clip removed - piston comes out.

Remove primary piston.

 Remove secondary piston, by”tapping “on block of wood or applying a small amount of air pressure to front port hole, where the brake line was.

 Secondary piston partially out of bore; remove it.

Secondary piston removed from bore.  

Inspect the bore, for scratches, pitting, rust, etc. 

 Inspect the master cylinder interior.

Parts after removal.

You can inspect the old parts, for pitting,or damaged seals, this one had pitted piston.

Pitted piston 

 Pitted piston 

Reassembly

Re-assembly is done in reverse order; install the secondary piston, the primary piston, and then the circular clip.

The re-assembly process will be much easier if you soak the parts in clean brake fluid prior to reassembling the unit.

Make sure all parts and the bore are very clean.

Bleed master cylinder on the bench.

The entire rebuild including removal from vehicle, disassembly, rebuilding, bleeding and re-installing took about one hour.

Kit used ordered from Wilcox.

Kit # 28978. Cost about $25

Tools used in this rebuild.

Rebuilt, cleaned and as good as new!