Graco 104126 Boss Plug

Technical Overview & Compatibility for Graco 104126 – Boss Plug

The Graco 104126 Boss Plug is a hex-head sealing plug with 3/4-16 UNF threads used to close a threaded “boss” port in Graco fluid systems—commonly seen on high-pressure filter modules and select air-operated diaphragm pump assemblies. Always verify fit against your machine’s parts list before ordering.

Compatible Machines (to verify)

Commonly used where a 3/4-16 UNF boss port needs sealing; check your parts manual for 104126 specifically.

• Graco high-pressure / medium-volume filter assemblies (“Red Alert” style) – boss port plug
• Selected Graco air-operated diaphragm pump systems – unused or service port plug
• Other Graco sprayers that incorporate a 3/4-16 UNF boss in the filter/manifold block

Key Specifications

Usage Notes & Safety

• Confirm the boss port is 3/4-16 UNF and that the parts list calls out 104126.
• Depressurize and drain the system before removal/installation to avoid fluid injection hazards.
• Clean threads and apply the sealant specified by Graco for your system.
• If your manual lists 104442, check if 104126 is the approved replacement before use.