Overview
Modified brass orifice housing bushing. HydraMaster part number 000-052-423, listed as Bushing, Modified Set Screw Orifice and, in newer manuals, Fitting, Bushing Modified Orifice Housing.
The bushing houses the set-screw orifice that meters solution flow in the high-pressure manifold. It is not an ordinary reducing bushing — it is machined to accept the orifice set screw, which is why an off-the-shelf bushing of the same thread sizes will not do the job.
What it fits
Named in the Hi-PSI manifold assembly of:
- Boxxer 421 — item 4, 2 fitted
- Boxxer 427 — item 3, 1 fitted
- Boxxer 423S — item 5, 2 fitted
- Boxxer 318 — 2 fitted
- Boxxer 323HP — 1 fitted
- Titan 425 — 2 fitted
- MAXX 450D / 470D / Diesel — item 4, 2 fitted
- Crossfire 4.2 — Bushing, Mod. Set Screw Orifice Housing, 1 fitted
- DriMaster Rotary tool — item 11, 1 fitted
What goes with it
The orifice set screw itself is a separate part, and the size of that screw is what determines flow:
- 180-004 — Orifice, Set Screw 0.033"
- 180-006 — Orifice, Set Screw 0.061" (not currently a stocked CCW line)
Machines are built with a specific orifice size. Changing it changes solution flow and pressure behaviour. Do not fit a different size on assumption — check the parts list for your model.
Fitting advice
Note the orientation and the depth of the orifice screw before you strip the assembly, and take a photo. It is the sort of detail that is obvious while the parts are in front of you and impossible to reconstruct afterwards.
Check the assembly drawing for your machine for the sealant specification. HydraMaster call it out explicitly on the manifold drawings, and it is not the same on every joint.
Frequently asked questions
Does it come with the orifice screw?
No. The set screw is a separate part number — 180-004 or 180-006 depending on the machine.
Can I use a standard brass reducing bushing?
No. This one is machined to house the orifice set screw. A standard bushing will not hold it.
How many does my machine take?
One or two depending on the model — see the list above.
My pressure is unstable. Is this the part?
Possibly, but check the simple things first: the ¼ inch Y strainer screen, the orifice itself, and the by-pass valve seals. An unstable reading is more often a blocked orifice or worn by-pass seals than a failed bushing.
Rebuilding a Hi-PSI manifold? Send us the machine model and serial number and we will put together the full set of parts from the assembly drawing so nothing is missed.
