Clean & Maintain Your Graco Airless Correctly: The Pro Guide for GX21 & GX19
Thorough cleaning is essential for long service life of your airless sprayer. This step-by-step guide shows you how to safely and effectively clean, maintain, and store your Graco GX21 or GX19 after work — whether you used water-based or solvent-based coatings.
The 3 Golden Rules Before Cleaning
1. Always release pressure!
The system remains under high pressure (up to 207 bar) even after switching off. Before EVERY service, tip change, or cleaning step, you MUST perform the pressure relief procedure. This is vital!
2. Solvents = Grounding!
If you clean with thinner, mineral spirits, or other flammable liquids, you MUST ground the unit and the waste container. Connect the grounding cable to a water pipe or a grounded outlet.
3. Use the correct cleaning agent
Water for dispersion paints; suitable solvents (e.g., universal thinner) for lacquers and oil-based materials. Never use chlorine-containing bleach or halogenated hydrocarbons!
Step 0: Safely Release Pressure (Mandatory!)
This procedure is the first step of ANY cleaning or maintenance.
- Secure the gun: Activate the gun trigger lock.
- Switch off the unit: Set ON/OFF switch to OFF. The light goes out.
- Reduce pressure: Turn the pressure control knob fully to the left to the lowest setting.
- Empty the gun: Hold the gun firmly into an empty bucket, release trigger lock, and pull the trigger until no pressure builds up.
- Empty the system: Place the drain hose into a bucket. Set the Prime/Spray valve to PRIME to release remaining system pressure.
- If clogging is suspected: Loosen the nut on the tip guard or hose connection VERY SLOWLY to release pressure gradually.
⚠️ Critical Safety Warning
NEVER spray solvent through the tip! Fine atomization and resulting fumes pose an extreme explosion risk. Always remove the tip and tip guard before solvent cleaning and clean them separately in a bucket with thinner.
Cleaning: Which Method for Which Model?
The procedure depends on your sprayer type and the material sprayed. Select your scenario:
A) GX21 Stand Model (with suction tube) – Standard Cleaning
For both water-based AND solvent-based materials.
- Release pressure (see above). Remove tip and tip guard.
- Remove suction tube from paint, wipe clean. Separate suction and drain hose.
- Place suction tube into a bucket with cleaning fluid (water/thinner). Drain hose into waste bucket.
- Set pressure control to Prime/Clean (lowest speed). Set Prime/Spray valve to PRIME.
- Switch on the unit and flush through about 1/3 of the cleaning liquid. Switch off.
- Recover paint from hose: Hold gun in paint bucket, pull trigger, turn valve to SPRAY, briefly run unit until diluted paint appears.
- Immediately redirect gun into waste bucket and continue spraying until clear fluid comes out.
- Lock gun, set valve to PRIME, switch off unit.
- Clean filter (Step 4), fill unit with Pump Armor (Step 5).
B) GX21 – Power Flush (water-based only!)
Faster cleaning after water-dispersion coatings using a garden hose.
- Release pressure. Remove tip and tip guard.
- Attach Power-Flush adapter to garden hose, turn on water, and rinse suction tube/strainer.
- Connect hose plus adapter to suction tube. Keep drain hose in waste bucket.
- Turn on unit, open water flow, and flush for 20 seconds. (Steps 6–8 same as in A.)
C) GX19 / GX FF Hopper Model – Cleaning
For both water-based AND solvent-based materials.
- Release pressure. Remove tip and tip guard.
- Pour remaining material out of hopper. Remove drain hose from hopper and place into waste bucket.
- Fill hopper with cleaning fluid (water/thinner).
- Set pressure to Prime/Clean. Run unit and flush approx. 1/3 of fluid. Switch off.
- Remaining steps (recover paint from hose, etc.) follow procedure A, steps 6–9.
For Long Service Life: The Right Accessories
Always use original Graco replacement parts and high-quality accessories such as suitable high-pressure hoses and cleaning fluids to maintain warranty and ensure optimal results.
Discover Graco Airless & AccessoriesStep 4: Clean Filters and Gun
These components are prone to clogging and should be maintained after every use.
InstaClean™ Fluid Filter (optional)
- After relieving pressure and removing battery, disconnect hose from unit.
- Unscrew outlet fitting and remove filter.
- Check filter for debris and clean with a soft brush in water/thinner.
- Reinsert filter with the closed (square) end first, tighten fitting.
Gun & Gun Filter
- Gun filter (in the handle) should be brushed clean at every cleaning. Replace damaged filters.
- Tip & tip guard should be cleaned separately in a bucket with cleaning fluid.
- Wipe outer gun with a soft, damp cloth.
Step 5: Proper Storage with Pump Armor™
This protects your pump from corrosion and ensures it's ready to go for the next job.
- Release pressure and ensure all water/cleaning residues are removed from hose and system.
- Flush in Pump Armor:
- GX21: Place suction tube into Pump Armor bottle, drain hose into waste bucket.
- GX19: Pour Pump Armor into hopper, drain hose into waste bucket.
- Set Prime/Spray valve to PRIME. Switch on unit and increase pressure until pump starts running.
- As soon as storage fluid exits the drain hose (after 5–10 seconds), switch off unit.
- Set Prime/Spray valve to SPRAY. This keeps the storage fluid inside the pump.
- Remove batteries. Place suction and drain hoses into a plastic bag for safety.
Important: NEVER allow water to freeze inside the pump or remain inside for long periods — this will cause severe damage.
Quick Checklist: Routine Maintenance
| Task | Interval | Purpose |
|---|---|---|
| Clean gun filter | Every use | Prevent clogs |
| Clean inlet strainer | Every use | Protect pump from debris |
| Check InstaClean filter | Every use | Optimize flow & spray pattern |
| Check air vents | Regularly | Prevent motor overheating |
| Inspect high-pressure hose | Before every use | Safety — prevent hose burst |
Conclusion
Investing 15–20 minutes for careful cleaning and storing with Pump Armor after each workday pays off multiple times: you avoid costly repairs due to dried paint or corrosion, ensure reliable performance for your next project, and significantly extend the life of your valuable Graco airless sprayer. Always remember the three golden rules: release pressure, ground when using solvents, and use the correct cleaning agent.
