Graco 239937 Piston Valve

The Graco 239937 Piston Valve is a genuine OEM replacement part designed for maintaining proper fluid flow and pressure in your airless sprayer’s pump section. It ensures consistent performance and prevents pressure loss during spraying.

Maintains proper pump suction and discharge flow
Ideal for Ultra, Ultra Max, and 190ES sprayers
Restores lost pressure and spray consistency
Durable OEM stainless and metal body construction

Retail Price: $69

You save: $5.24 (7.59%)

Our Price: $63.76

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Description

Product Overview: Graco 239937 Piston Valve

The Graco 239937 Piston Valve is a critical pump valve that controls fluid flow in select Graco airless sprayer fluid sections. It helps restore pressure, prime consistency, and long-term sealing performance when the original valve is worn.

Compatible Machines

This valve is used on the following Graco airless sprayer families / generations (check your exact model or pump part list to confirm fit):

Ultra 390 / 395 (select generations)
Ultra 490 / 495 / 595 (select generations)
Ultra Max 695 (commonly listed for 1st & 2nd series)
190ES (select units)

Key Features & Quick Specs

Part Number	239937 (also written as 239-937)
Function	Pump piston check/valve controlling intake & discharge flow in the fluid section.
Typical Construction	Metal body, stainless/seat components (OEM configuration as supplied by Graco).
Common Use Cases	Loss of pressure, hard priming, pulsation, or leakage due to a worn piston valve.
Cross-Reference	Replaces 239-937. Also available within select rod/valve kits (see below).

Related Pump Rod / Valve Kits

24W617 – Piston Valve & Rod Kit for PC fluid sections (contains valve 239937)
249125 – Rod & Piston Kit for standard (pinned rod) models

Fit & Identification Notes

Compatibility can vary by generation and fluid section even within the same model family.
Confirm by checking your sprayer’s pump bill of materials (BOM) or the label on your existing fluid section.
If your pump number matches one of the Graco pump assemblies that use this valve (e.g., 17C487, 17C488, 17C489, 17C721, 17M992, 24Z731), 239937 is typically correct.

Frequently Asked Questions

Match your model family, generation, and fluid section against your parts list. If your pump assembly is listed among common matches (e.g., 17C487/17C488/17C489/17C721/17M992/24Z731) or your manual lists 239937, you’re good to go. When in doubt, share your model & serial for a check.

Hard priming, loss of pressure at the gun, pulsation/surging, paint bypass or leakage into the wet cup, and inconsistent spray pattern are common signs the piston valve/seat is worn and needs replacement.

If your rod is in good condition, the 239937 valve may be all you need. If the rod is pitted, bent, or worn, consider the appropriate kit (e.g., 24W617 for PC sections or 249125 for standard sections) to restore sealing and longevity.

Clean the fluid section thoroughly, inspect the seat & rod, use proper torque per the service manual, and replace any damaged seals or packings. A lightly oiled, clean assembly helps avoid galling and ensures proper seating on first start-up.

OEM configurations are metal-body with stainless components appropriate for professional water-borne and many solvent-borne coatings. Always follow coating compatibility guidelines in your sprayer manual.