Graco 158891 Piston Stud

The Graco 158891 Piston Stud is a genuine OEM part designed for Graco displacement pumps. Ensures proper piston alignment and reliable pump performance.

Part Number: 158891
Type: Stud, Piston
Compatible Models: 205585, 205584, 203367
Manufacturer: Graco
Torque Spec: 20‑30 ft‑lb (27‑41 N·m)

$85.25

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Description

Compatible Equipment for the GRACO 158891 Piston Stud

This replacement part — the GRACO 158891 “Stud, Piston” — is used in certain displacement‑style pumps manufactured by Graco. It is referenced as Ref. No. 107 in the displacement pump assembly of compatible machines.

Machine Model	Series	Description
205585	D	5 Gallons Duo Paint Sprayer pump assembly includes part 158891
205584	A	5 Gallons Duo Paint Sprayer pump assembly includes part 158891
203367	B	Displacement Pump (Ref. 107 = part 158891)

Product Overview

Specification	Details
Part Number	158891
Description	Stud, Piston (also listed as “Body, Piston”)
Manufacturer	Graco
Torque	20‑30 ft‑lb (27‑41 N·m)
Function	Mounts piston assembly inside the displacement pump, ensures proper alignment

Frequently Asked Questions

If the stud is worn, bent, or improperly torqued, the piston assembly may mis‑align, leading to fluid leakage, pump inefficiency, or premature wear of the piston, cylinder, or packing components.

It is strongly recommended to use the exact part number listed in your machine’s parts diagram. Using a non‑specified part can compromise performance or safety.

Installation is straightforward for qualified maintenance technicians. After relieving system pressure, unscrew the old stud, remove the piston and washers, install the new stud, and torque it to the correct value (20‑30 ft‑lb). Refer to the manufacturer’s instructions.