Graco 189316 Displacement Rod

The Graco 189316 Displacement Rod is a precision stainless-steel piston rod designed for heavy-duty Graco pump lowers. It transfers motion between the drive and piston to ensure consistent spray pressure and smooth operation.

Durable stainless-steel construction for long service life
Essential for pump rebuilds and sealing performance
Fits Dura-Flo, Bulldog, King, and NXT Dura-Flo pump series
Replaces worn or scored rods to restore efficiency

$1520

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Description

Compatibility & Fit – Graco 189316 Displacement Rod

Use the list below to quickly confirm whether the Graco 189316 Displacement Rod matches your pump series. Always verify by lower pump section and ratio.

Roof Rig GH 5030 (pump assembly)
Senator / Dura-Flo 900 series – 17:1 ratio
Bulldog series – 28:1 ratio
King series – 56:1 ratio
NXT Dura-Flo series – X16:1 and X30:1 ratios

Part Details

Part Number	189316
Item Name	Displacement Rod (also called piston rod)
Material	Stainless steel
Application	Industrial air-motor/gear-driven displacement pumps (lower pump section)
Function	Transfers motion from the drive to the piston/valve assembly; draws in material on the up-stroke and discharges on the down-stroke
Fit Guidance	Match by series, ratio, and lower-end bill of materials; check your manual before ordering

Overview

The Graco 189316 Displacement Rod is a wear component in the pump’s lower section. Because it operates under load with reciprocating seals/packings, it can wear or score over time. Replacing a damaged rod restores sealing, output consistency, and pump life.

When to Replace

Visible scoring, pitting, or bending on the rod
Frequent packing leaks or poor prime/pressure stability
Full lower-end rebuild (recommended to inspect/replace the rod with packings and seats)

Installation Tips (General)

Confirm part number against your pump’s manual and ratio
Inspect cylinder and packings; replace worn components together
Lubricate per manufacturer guidance and torque fasteners to spec
Flush and pressure-test before returning to service

Frequently Asked Questions

Check the pump series, ratio (e.g., 17:1, 28:1, 56:1, X16:1, X30:1), and the lower-end parts list in your owner’s/service manual. Match the displacement rod number exactly before ordering.

In these pump lowers, the terms are often used interchangeably. The part links the drive to the piston/ball assembly and works with packings to create suction and discharge.

Scored/bent rod, packing leaks, loss of pressure, hard priming, or pulsation under steady load all point to lower-end wear that may include the rod.

It’s good practice to service the full lower (packings, seats/balls, and rod) together. This restores sealing and extends service intervals.

Only if the sprayer’s pump lower is one of the listed series/ratios and the manual specifies 189316. Always confirm by part number in the documentation for your exact unit.