Graco DutyMax EH/GH300 HD Standard Series Spray Gun & Hose Parts

Graco DutyMax GH300 HD – Spray Gun & Hose Parts Breakdown

The Graco DutyMax GH300 HD is a heavy-duty hydraulic airless sprayer that powers through tough materials like elastomerics, roof coatings, and fireproofing. But when you need consistent output—and minimal downtime—the right paint sprayer parts make all the difference. This guide drills into the components and accessories that keep your GH300 HD system spraying strong.

Core Components You'll Use Daily

1. Graco Airless Spray Gun – Inline Heavy-Duty Texture

• Designed to withstand high-stress applications

• Comes with stainless fluid path and Teflon-packed piston

• Compatible with graco magnum x7 parts, including RAC X guards for quick tip swaps

2. High-Pressure Hoses & Fittings

• Standard ½″ ID BlueMax II hoses rated 3,300 psi

• Available lengths: 50, 75, 100 ft (model 278499 etc.) plus 3/8″ whip hoses (model 191239) for tight quarters

• Includes high-pressure fittings and 360° swivels

3. RAC X Tips & Guards

• Picks like RAC X FFLP, E‑XHD, and heavyweight reversible nozzles for versatility

• Compatible with both texture and fine coatings

• Works great with graco fine finish sprayers for consistent, crisp lines

4. Filters, Strainers & Seals

• Mesh gun filters (20, 40, 60, 100) to match material viscosity

• In-gun strainers and tip filters prevent clogs

• Seal kits include piston packings and check-valve parts for rebuilds

5. Hit-and-Miss Accessories

• Trigger packs, guard extensions, tip extensions, and mounting brackets

• Fast-coupler kits for quick hose or shutoff replacements

Why Original Parts Matter

Working pressure up to 3,300 psi isn’t forgiving—cheap clones rarely hit factory specs. Genuine Graco components stand out because they:

• Meet tight OEM tolerances for flawless fluid flow

• Are chemically resistant to harsh elastomerics and solvent primers

• Keep your warranty intact and reduce service calls

• Seamlessly support graco magnum x7 parts, making cross-fleet compatibility a breeze

Maintenance & Service Tips

Flush & Clean Regularly

Clear hoses and guns post-job to avoid buildup, especially when switching from textures to stains.

Change Filters Monthly

Mesh filters should align with tip size: coarse material (30‑40 mesh), general coatings (60 mesh), fine finishes (100 mesh).

Check Hose Wear

Bulges or kinks can affect pressure—replace affected sections immediately to prevent downtime.

Use RAC X Guards

Tip guards reduce wear and make changing graco spray tips faster on-site. Carry spares.

Have Rebuild Kits Handy

Seal failures can be fixed quickly with graco pump repair kits—no need to replace an entire gun assembly.

Seek Professional Service

When pressure falters or fluid leaks persist, search for graco pump repair near me. Many centers can repair rods, seals, pistons, or offer full rebuilds.

Cross-Compatibility & Fleet Versatility

• Graco Magnum X7 parts compatibility includes RAx tips, hose kits, and guards that fit seamlessly with your GH300 HD guns

• Hose couplers and filters often match other Graco guns and graco electric paint sprayer systems

• Shared consumables simplify inventory across rental fleets, DIY rigs, and contractor carts

Top-Moving Items to Keep in Stock

1. Contractor PC & SG3 Gun Kits – Ergonomic, high-flow handles

2. BlueMax II Hoses – 50/75/100 ft with swivel ends

3. RAC X Tip & Guard Sets – LP 517, FFLP, E-XHD options

4. Easy-Out™ Filters – 30, 60, 100 mesh sets

5. Seal & Piston Kits – OEM rebuild packs

6. Whip Hoses & Shut-Off Fittings – For quick replacements

7. Trigger & Guard Kits – Handle case damage

8. Extension Wands & Shields – For precision and clean lines

Pro Tips for Long-Term Performance

• Warm-flush hoses (~110°F water) after using thick elastomeric coatings—reduces cleanup time and extends hose life

• Wet-cup application: dab Throat Seal Liquid to prevent rod wear during idle periods

• Re-torque hoses monthly (recommended torque 100 N·m) to prevent leaks

• Stock essential parts: ensure one extra hose, tip, guard, and filter kit on-site

• Label parts by job types: e.g., “Roof Kit” includes 0.047″ LD tip and coarse filter; “Finishing Kit” uses LP tips and 100-mesh

Ideal Use Cases for This Setup

The DutyMax GH300 HD system works outstandingly in:

• Roof coating and waterproofing, thanks to its long-stroke pump

• Fireproofing in industrial buildings—heavy coatings handled smoothly

• Elastomerics on commercial complexes with high spray volume

• Fine finish sprayers too—even though heavy-duty, it supports precision tips and guards

When to Repair or Replace

If you experience:

• Recurrent filter clogs, uneven strokes, or popping trends

• Gun sputtering or loss of prime

• Seal leaks or pressure drop even after filter swaps

…then it may be time for a full rebuild or graco replacement pump assembly. Authorized service centers—just search graco pump repair near me—can handle part swaps faster and better than field DIY attempts.

Final Takeaway

From the inline spray gun to the whip hose and RAC X guard, every component in your DutyMax GH300 HD system is mission-critical. Match high production needs with quality paint sprayer parts, guard your guns with RAC X tips, and show tanks to accessories designed for both graco electric paint sprayer lines and rugged hydraulic rigs.

Carry spares, maintain filters, and keep graco fine finish sprayers ready for detail work. And when fluid sections age, exact-fit graco replacement pump assemblies restore flow precision fast. With authentic parts and the right local support, you’ll stay spraying strong—anywhere, anytime.