Graco 236786 Pump Cylinder Kit

The Graco 236786 Pump Cylinder Kit is a genuine OEM fluid-section cylinder designed to restore smooth performance and seal integrity in select Graco 390 and NOVA sprayers.

Ensures precise fit and factory-grade performance
Replaces worn or damaged pump cylinder
Compatible with 390 ST/STS, NOVA SP/SPX, and Pro 301 ST series
Helps eliminate leakage and pressure loss

List Price: $247

You save: $64.71 (26.20%)

Sale Price: $182.29

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Description

Overview & Key Details

The Graco 236786 Pump Cylinder Kit (also written as 236-786) is the OEM fluid-section cylinder used on select Graco 390-class and NOVA-series airless sprayers. Replacing a worn cylinder helps restore sealing surface quality for packings/rod, improving pressure stability and reducing leaks.

Compatible Machines

Fits the following Graco/related models (verify with your sprayer’s parts manual):

NOVA SP
NOVA SPX (old version)
Pro 301ST (Fuller O’Brien)
Pro 301STS (Fuller O’Brien)
PRO 501ST (Fuller O’Brien)
390 Duron (a.k.a. 390 Performance/Duron)
390 ST
390 STS
290 Easy (select variants)

Part Details

OEM Part	Graco 236786 Pump Cylinder Kit
Also Known As	236-786
Assembly Note	Often referenced with pump assembly #236787 (check your model’s breakdown).
Function	Fluid-section cylinder that houses the rod/packings in the airless pump.
Category	Airless sprayer pump cylinder / fluid-section component
Genuine/OEM	Yes — OEM Graco replacement part

Why Replace the Cylinder?

Restores a smooth, in-tolerance sealing surface for packings/rod.
Helps recover pressure consistency and reduce bypass/leakage.
Extends service life of Graco 390-class and NOVA pumps when combined with fresh packings.

What’s Typically Involved

De-pressurize and flush the unit per Graco’s safety procedure.
Remove the fluid section; inspect rod/packings and check valve parts.
Install the new pump cylinder, then rebuild with correct packings/torque per manual.
Prime with solvent/paint, check for leaks, and verify pressure/atomization.

Notes & Cross-References

Common Series	Graco 390 ST / STS, 390 Duron, NOVA SP/SPX, Pro/PRO ST variants
Related Pump Assy	Often noted with Pump #236787 (verify per model breakdown)
Best Practice	Replace packings and check ball/seat if wear is evident when installing a new cylinder.

Frequently Asked Questions

Yes. It’s the same Graco part; some listings include the hyphen (236-786) and others don’t (236786).

It is commonly listed for NOVA SP, NOVA SPX (old), Pro 301ST/301STS (Fuller O’Brien), PRO 501ST, and Graco 390 series including 390 Duron, 390 ST, and 390 STS, plus select 290 Easy variants. Always verify with your exact parts manual before purchase.

It’s best practice to inspect and often replace the packings, seals, and check components during a cylinder swap. Follow your model’s service manual for the correct kit numbers and torque specs.

Yes — it’s a genuine Graco pump cylinder for the listed sprayer families when specified in their parts lists.

Symptoms include difficulty holding pressure, visible scoring or wear, accelerated packing wear, or persistent leakage at the rod. If present, replacing the Graco 236786 Pump Cylinder Kit with fresh packings typically restores performance.