Graco Gmax 3900 ProContractor & IronMan (16X821) Series Gas Airless Sprayer Parts List

Graco GMAX 3900 ProContractor / IronMan (Model 16X821) – Full OEM Parts Guide 

For professionals who count on serious power and dependability, the Graco GMAX 3900 ProContractor / IronMan Series (16X821) stands out as a top-tier graco airless paint sprayer. Whether you're preparing surface coatings on large projects or driving fleet performance, having access to authentic graco paint sprayer parts is essential. This guide delivers an all-inclusive graco parts list, organized for easy reference while fitting naturally into maintenance workflows with graco magnum x7 parts compatibility and graco pump repair kits integration.

1. Engine & Drive Cart Components

Built for field ruggedness:

• Gas Engine (Honda 5.5 HP) – Delivers reliable long-term power, supporting high-volume applications in any terrain.

• Mounting Frame & Cart Assemblies – The ProContractor and IronMan versions use separate hose-reel carts (Model 24D047) built for durability and easy transport 

• Cart Hardware – Includes pneumatic wheel kits (119509), retaining clips, frame washers, leg caps (276974), and ground straps—the essentials for mobility and safety

These chassis parts are interchangeable across other Graco models, making them ideal for shared inventories.

2. Fluid Section: Pump & Manifold

The backbone of the GMAX sprayer:

• Pump Variants – The standard ProContractor pump section (16X414 / 16Y598) seats right behind the engine, supported by ProConnect assemblies. It’s the same powerful section as found in Magnum X7 sprayers .

• Supplies & Manifold Filters – Features Easy‑Out filters in 30, 60, 100, and 200 mesh options, plus inlet strainers (189920) to upkeep flow quality and reduce contamination 

• Drain Valve Kit – Heavy-duty prime valves make flushing and cleanup simple—essential for smooth maintenance routines.

OEM pump sections align with graco pump repair kits, offering seamless swap or rebuild capabilities.

3. Control Box & Pressure Management

Professional operation requires precise control:

• Control Box (16X821) – Houses potentiometer, toggle/rocker switches, gaskets, and strain relief grommets for a sealed interface 

• Pressure Transducer & Wiring – Ensures reliable pressure feedback for smooth adjustable performance.

Those maintaining across fleets find great symmetry between the GMAX control system and their Magnum X7 setups.

4. Spray Gun, Hose & Accessory Kit

The finishing tools:

• Contractor Gun (288420) – Equipped with RAC-X tips, this gun is optimized for high-volume consistency and is compatible with various Graco sprayer lines 

• High‑Pressure Hose (240794, ¼″×50 ft) – Rated for full 3,300 psi operation, it integrates seamlessly with all ProContractor and IronMan systems.

• Accessories – Includes adapters, whip hoses, and tip guards to protect the tip and improve spray control.

This arrangement is perfect for fleet environments where interchangeability between graco airless spray guns matters.

5. Pump Repair Kits & Spare Components

Essential for minimizing downtime:

• Graco Pump Repair Kits – These kits include OEM packings, O-rings, check valves, pistons, and springs. Designed expressly for the ProContractor pump, they enable complete rebuilds with guaranteed fit and performance.

• Individual Pump Parts – Available for incremental maintenance, great for emergency repairs in the field.

You’ll keep spraying longer by stocking the right parts during preventive maintenance.

6. Fluids, Filters & Prevention

Maintaining hydraulic cleanliness:

• Liquid Filters & Inlets – Standard 244067–244071 filters and 189920 strainers preserve fluid integrity 

• Deflectors & Drain Tubes – Included for convenient cleanup and system drainage after use.

These parts keep your sprayer operating at peak capacity and ready for immediate deployment.

7. Shared Parts Across Systems

Inventory smart—stock once for multiple machines:

• Magnum X7 Compatibility – Pistons, valves, packings, hoses, and tips cross-function seamlessly with GMAX 3900 units.

• Magnum X7 Parts Integration – Makes stocking personnel more efficient across equipment fleets.

8. Maintenance Schedule & Service Tips

Preventive schedule outline:

• Daily: Clean tips, flush lines, depressurize pump, visually inspect hoses.

• Weekly (50 hrs): Replace mesh filters; add TSL to fluid sections.

• Monthly (200 hrs): Use graco pump repair kits to refresh flow seals; inspect hoses.

• Every 500 hrs: Full pump rebuild or replacement; check engine oil; secure frame bolts and switch gear.

• Annually: Perform full system breakout, inspect pump, manifold, rods, and gun components.

9. Certified Service: “Graco Pump Repair Near Me”

Searching "graco pump repair near me" locates local, certified Graco technicians qualified to perform rebuilds using OEM graco pump repair kits. These pros ensure exact specifications are met—keeping equipment warranty intact and performance optimized.

10. Complete Parts Reference Overview

• Chassis & Mobility: Frame 24D047, wheel kit 119509, cart clips & handles

• Pulse Section: Pump 16X414 / 16Y598, ProConnect housing, packings

• Filters & Hoses: Easy‑Out 244067–71 filters; suction hose 24U917; HP hose 240794

• Control Box: 16X821 module with potentiometer, switch, gasket & transducer

• Spray Gun: 288420 Contractor Gun, RAC-X tips, adapter kits

• Rebuild Kits: Full pump kits and individual replacement parts

• Consumables: Filters, O-rings, TSL, tip guards, deflectors

Final Takeaway

The Graco GMAX 3900 ProContractor / IronMan Series delivers the power, reliability, and interchangeability modern painters demand. By leveraging a unified graco parts list, stocking graco magnum x7 parts, and utilizing graco pump repair kits, you ensure longevity and safety at scale. Add certified rebuild support through local searches like graco pump repair near me, and you’ve got a sprayer fleet that’s ready for anything—from textures to smooth finishes, indoors and out.