Master Cylinder Reassembly

  • If replacing the primary piston, secondary piston, or master cylinder body, check and adjust the pushrod clearance before installing the master cylinder.
  • Clean all the parts in brake fluid and air dry; blow out all passages with compressed air.
  • Before reassembling, check that all the parts are free of dust and other foreign particles.
  • Replace parts with new ones whenever specified to do so.
  • Use only genuine DOT3 Honda brake fluid. Non-Honda brake fluid can cause corrosion and shorten the life of the system.
  • Do not mix different brands of brake fluid as they may no be compatible.
  • Replace the master cylinder if the bore is damaged or worn. Do not hone or attempt to refinish the bore.
  • Coat the piston cups, pressure cup and master cylinder bore with clean brake fluid.
  • Use recommended greases in the master cylinder seal set.

1.Install the reservoir seal in the groove of the reservoir cap.

2.Install the strainer, assembled reservoir cap, and new grommets on the reservoir.


3.Coat the cups (A) of a new primary piston (B) with clean brake fluid, then install the primary piston into the master cylinder.

NOTE: On vehicle's with ABS, check that the valve stem (C) moves smoothly by lightly pushing it through the slot in the piston. Install the piston so the slot in the piston aligns with the stop pin hole in the master cylinder.

With ABS 

Without ABS 

4.Coat the cup (A) of a new secondary piston (B) with clean brake fluid.


5.Apply recommended seal grease in the master cylinder seal set to the secondary cup (C), then install the secondary piston into the master cylinder.

6.On vehicle's with ABS; align the slot in the primary piston with the stop pin hole (A) by pushing the secondary piston (B) in, and install the stop pin (C).


7.Install the reservoir (D) to the master cylinder.

8.Install the new circlip (A) while pushing in the secondary piston (B).


9.Adjust the pushrod clearance .

10.Apply recommended seal grease in the master cylinder seal set to a new rod seal, and install the seal onto the brake booster.