Airless sprayer troubleshooting

Short answer: most airless faults come down to air in the suction, a blocked filter or tip, a stuck inlet ball or worn packings. Work through the checks below in order. Clean before you replace. On a job, the quickest way back to spraying is usually a clean filter, a new tip or a spare part you already carry.

What is it doing? Tap the one that sounds like yours.

• Spits or blocks
• Tails in the fan
• Won't prime
• Won't hold pressure
• Leaks
• Stopped mid job, full of paint

Also on this page: read your fan, after every job and paint injection injury. Read the injury warning before you work on a machine.

Paint injection injury: always serious

An airless sprayer can push paint through your skin. We've had customers inject paint by accident, and they could have been seriously injured if they hadn't taken it seriously.

Graco's warning: "High-pressure fluid from gun, hose leaks, or ruptured components will pierce skin. This may look like just a cut, but it is a serious injury that can result in amputation. Get immediate surgical treatment." (Graco manual 3A6285M, page 3)

If it happens to you or anyone on site: go straight to a hospital emergency department. Tell them it is a high pressure injection injury, and take the paint's SDS (safety data sheet) with you so they know what went in.

To stop it happening, Graco's warnings say (manual 3A6285M, page 3, unless noted):

• "Engage trigger lock when not spraying."
• "Do not point gun at anyone or at any part of the body."
• "Do not put your hand over the spray tip."
• "Do not stop or deflect leaks with your hand, body, glove, or rag."
• "Do not spray without tip guard and trigger guard installed."
• "Follow the Pressure Relief Procedure when you stop spraying and before cleaning, checking, or servicing equipment."
• "Check hoses and couplings daily. Replace worn or damaged parts immediately."
• "Equipment maintains pressure after power is shut off." (Graco manual 3B0070E, page 10)

Before you start

Always do the pressure relief procedure in your manual before you touch the tip, filter or any fitting. In short: lock the trigger, turn the sprayer off and unplug it. Hold the handpiece against a bucket and trigger it to release pressure, then open the prime valve. Lock the trigger again.

Never hold a leak with your hand or a rag. Read paint injection injury above before you start.

Won't prime or won't pick up paint

The motor runs but no paint comes up the suction tube.

1. Prime valve. Make sure it's open (prime) and the return tube is in the bucket.
2. Suction tube. Check it's in the paint, the inlet strainer is clean and the fitting is tight. An air leak here stops it priming.
3. Inlet strainer. Clean it. A blocked strainer starves the pump.
4. Stuck inlet ball. Common after storage or when paint has dried in the pump. Gently tap the inlet valve housing, or remove it and clean the ball and seat.
5. Paint too thick. Check the paint maker's data sheet for thinning.
6. Worn packings or valves. If it still won't prime after the checks above, the pump needs a repack.

Parts: inlet strainer, inlet valve, pump repair kit. Find them on your sprayer's parts diagram.

Won't build or hold pressure

Pressure won't come up, drops off while you spray or the sprayer pulses.

1. Tip too big or worn. A worn tip or one bigger than the sprayer's max tip will drop pressure. Check the tip size against your sprayer's rating and try a new tip.
2. Prime valve. Check it's fully closed (spray). A worn prime valve leaks back to the bucket.
3. Filters. Clean or replace the pump filter and handpiece filter. Match the mesh to the tip.
4. Suction. Look for air bubbles in the return tube, a loose suction fitting or a blocked inlet strainer.
5. Inlet and outlet valves. Residue on the balls or seats stops the pump building pressure. Clean them.
6. Packings. If paint leaks from the top of the pump or pressure fades after a few seconds, the packings are worn. Repack the pump.

Send it in if the pump runs but won't build pressure after these checks, if there's an electrical fault or if it goes straight to full pressure and won't regulate. Email us the model and serial number.

For the Endurance Vortex pump (19D873) on the Ultra 390, 395, 450, 490 XT and 495 XT, the pump repair kit is 18B260, per Graco pump manual 334599.

From Graco pump manual 3A9391. Check the pump number on your sprayer before you order: Standard and ProContractor pumps take different kits.

Tails in the fan

Heavy lines at the top and bottom of the spray fan.

Tails? Turn up pressure, or thin the paint.

1. Pressure. Turn it up a little at a time until the tails close.
2. Paint too thick for the tip. Thin to the paint maker's data sheet, or try a smaller tip.
3. Worn tip. If the fan has narrowed and the tails won't close, fit a new tip of the same size.
4. Filters. A blocked filter drops the pressure at the tip. Clean it.

Test on cardboard before you go back to the wall.

Spitting or blocking

The fan spits, surges or the tip keeps blocking.

1. Air in the system. Check the paint level and the suction fitting. Re-prime.
2. Partly blocked tip. Lock the trigger, turn the RAC tip to reverse, unlock and trigger at a scrap board to clear it. Lock the trigger again and turn the tip back to spray.
3. Unstrained paint. Strain the paint through a strainer bag before it goes in the bucket.
4. Filter mesh. Use a finer handpiece filter for fine finish tips.
5. Spitting off an extension. Paint left in the extension drips when you let go of the trigger. A CleanShot shut-off valve at the tip stops it.

Read your fan

Spray a test on cardboard before you go back to the wall, then read the fan.

• Heavy lines at the top and bottom (tails): turn the pressure up a little at a time until they close. If they won't, the paint is too thick for the tip (thin to the paint maker's data sheet or try a smaller tip) or the tip is worn. See tails in the fan.
• A fan that has narrowed, with tails that won't close: fit a new tip of the same size.
• Spits, surges or keeps blocking: air in the system, a partly blocked tip or unstrained paint. See spitting or blocking.
• Pulses or fades while you spray: see won't build or hold pressure.

Leaks

At the hose ends

Relieve pressure first. Tighten the fitting with two spanners. If it still leaks, check the fitting and the hose end for damage. Replace a damaged hose. Never tape a high pressure hose.

At the tip or guard

Check the tip seal is in the guard and the guard is hand tight. A worn or missing seal leaks around the tip. Replace the seal.

From the handpiece

Paint from the handpiece body or around the trigger usually means worn needle seals. Rebuild the handpiece with its repair kit or replace it.

From the top of the pump

Paint at the top of the pump means worn packings. Repack the pump.

Repack it yourself or send it in?

• Repack on the bench: paint at the top of the pump, pressure that fades after a few seconds or a pump that won't prime after the suction checks. A repair kit and the pump manual are all most painters need.
• Send it in: electrical faults, a motor that won't run, a sprayer that goes straight to full pressure and won't regulate, gearbox noise or a pump that still won't build pressure after a repack.
• Crews: a spare pump or a second sprayer keeps the job going while one is on the bench. See service agents.

After every job

1. Do the pressure relief procedure in your manual and lock the trigger.
2. Flush as much paint out as you can before it sets.
3. Clean the inlet strainer, the pump filter and the handpiece filter.
4. Check hoses and couplings, and replace worn or damaged parts immediately (Graco manual 3A6285M, page 3).
5. Store the pump with Pump Armor.

Keep these in the van

Our list for keeping a sprayer earning on site:

• Spare tips in the sizes you run most, and a tip seal for each guard
• Handpiece filters and a pump filter in the mesh for your usual tips
• The pump repair kit and inlet seat kit for your pump
• Pump Armor for storage and Throat Seal Liquid where your pump uses it
• Two spanners for hose fittings, and the pump manual on your phone

Stopped mid job, full of paint

Relieve pressure, then flush as much paint out as you can before it sets. If the sprayer won't run at all, email spray@airlessspray.com.au straight away with the model, serial number and what happened. Don't leave paint sitting in it.

Still stuck?

Email us your sprayer, the paint and what's happening, with a photo if you can. We'll work through the checks with you and find the part on your diagram. Or open the parts finder, pick your sprayer and tap the part.