Rocket COFFEE MACHINE STEAM TAP REBUILD TUTORIAL

🛠 Tools & Parts You May Need

  • Flat & Phillips screwdriver
  • 21 mm / adjustable spanner
  • Needle-nose pliers
  • Food-safe grease (Molykote 111 or equivalent)
  • Rebuild kit (usually contains):
    • 2x O-rings
    • 1x valve gasket / seal

⚠ Safety First

  1. Turn machine OFF
  2. Let boiler cool or release pressure via steam wand
  3. Unplug from power
  4. Close water supply (if plumbed in)

1️⃣ Remove the Steam Knob

  • Rocket: usually unscrew the centre screw or pull off, depending on model
  • Quick Mill: remove top cap, then unscrew bolt under it
  • Slide knob off the valve shaft

2️⃣ Remove the Valve Assembly

  • Use 21mm spanner to unscrew the steam tap bonnet (top valve housing)
  • Pull the entire shaft assembly upward gently
  • Be careful not to drop internal spring or seals

3️⃣ Disassemble the Shaft

You will see:

  • Valve stem/rod
  • Spring
  • Rubber valve seal or gasket at the end
  • 2x O-rings on the stem

Steps:

  1. Remove old O-rings (use pick or fingernail)
  2. Remove valve seal at the end (it may be clipped or sitting loose)
  3. Keep spring aside safely

4️⃣ Install New Seals

  1. Lightly grease the stem
  2. Fit 2 new O-rings
  3. Install new valve gasket/seal at the end
  4. Place spring back in original position

5️⃣ Reinsert the Valve Into Machine

  • Push stem back into the steam valve body
  • Ensure it seats smoothly
  • Screw the bonnet/bonnet nut back down snug (don’t overtighten)

6️⃣ Reinstall Steam Knob

  • Slide knob back onto the shaft.
  • Tighten screw/bolt
  • Test open/close movement — should feel smooth, not gritty or stiff

7️⃣ Pressure Test

  1. Restore water supply
  2. Plug in and power ON
  3. When heated, test the steam tap:
    • No leaking from knob area
    • Full steam flow
    • Clean shut-off without dripping or hissing
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