Troubleshooting Guide For Graco Airless Paint Sprayers

Airless paint sprayers are not only efficient but cost-effective and fast. With the Graco Airless sprayer, you can cover a lot of area in a short amount of time.

The problem is that, like all other paint sprayers, they can lock up or get stuck.

Troubleshooting your paint spray gun can be a tedious and difficult task, especially if you aren't sure what the underlying problem is. We can help.

This article will look at all the possible issues you may encounter with your Graco sprayer. We will help diagnose the main cause and give you tips and options to solve the problem so you can get back to painting.

Airless sprayers have a lot of moving and internal parts. They also have removable parts that need to be cleaned and maintained. Even leaving the sprayer for a few hours can cause problems when you return.

Below we outline the most common issues and their solutions to get your Graco spray gun back to proper working order.

Whether you have a Graco Magnum Project Painter Plus, Graco X7, Graco 360, or Graco 190 ES, we've got you covered.

Graco Airless Sprayer

Airless Spray Gun Spitting

Paint sprayer spitting or spray pattern problems are arguably the most common problem with any sprayer.

There are several possible causes of spray pattern problems, and the problem can worsen when you use a nozzle extension.

When you release the trigger, a small amount of paint can form on the spraying tip, and when you go to spray again, it can splatter out of the spray tip orifice.

Other possible causes include debris or build-up on the spray tip guard or air bubbles inside the pump, hoses, and extensions.

You may also have dirty or worn-out fittings, packing, or assembly units, or your air pressure may be set too low.

Luckily, all of these causes are easy to diagnose and fix.

  • Inspect your air pressure. Ensure that the air pressure is high enough for the type of paint you are spraying and that there isn't a leak. If it is too low, it won't atomize properly and result in a splatter.
  • Prime the pump. Air in the pump or hoses is a result of an improperly primed pump. Priming will push out any air bubbles in the lines.
  • Clean the spray tip guard, nozzle, and fluid needle. Build-up, thick, dried paint and debris can accumulate that needs to be removed to ensure proper flow of the spray.

Does Not Operate At All

Sometimes you return to the job site and find that your sprayer won’t operate at all. This can be disheartening, but it can also be an easy fix.

The most common reasons included a closed or clogged spray tip outlet valve, the hose is obstructed or pinched, or there is dried paint or debris on the displacement rod.

If the problem persists, it could also be a dirty, worn, or damaged air motor, or finally, the runaway error on DataTrack is tripped.

To properly diagnose and repair these issues, check the following tips.

  • Inspect your power supply to ensure it’s live and working.
  • Check that the valves are open and clear the air lines. It may help to increase the air supply, too.
  • Clean your spray gun or airless hose, removing all build-up and debris and clearing all hoses. Replacement hoses may be needed.
  • Clean the displacement rod of dried residue or paint
  • Following the motor manual, properly clean, grease, and reseal the air motor
  • Reset the runaway monitor. Close the master valve, and wait for the air to bleed off. Press X to clear the code and reset the solenoid. Open the master air valve and restart your pump.

Does Not Absorb Paint

Occasionally, you will go to paint and find that the pick-up doesn't retrieve the paint from the paint cup. These are simple fixes, but first, you need to understand the issue.

The first thing to check is that the cup and lid are attached correctly and securely. If they are, check the adhesive inlet screen, gun filter, inline filter, and suction tube, which may be stuck or clogged.

To fix these issues:

  • Remove the paint cup and lid and reattach, making sure not to cross thread or leave loose.
  • Remove the adhesive screen and ensure it is clean, then return it into position properly.
  • Double-check filters, suction tube, fluid hose, and fluid supply levels in fluid section.
  • If you also notice paint leaks, check the prime pump, piston rod and piston packings, replacing as needed.

Draws In Secondary Air

The Graco VacuValve is responsible for the release of the air from the paint cup.

On the Graco Ultra and UltraMax models, when the valve is not properly closed or becomes defective, it can cause the unit to draw in air.

If you are drawing in secondary air through the paint cup, you can fix the issue fairly easily.

  • Clean or replace the VacuValve. First check the black valve for dried paint, gunk, or debris and clean it thoroughly. If the problem persists, unscrew the valve and replace it with a new one.
Scrub All Parts of Paint Sprayer

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Will Not Pump Or Will Not Pressurize

Sometimes you will encounter a problem where the unit will not pump, or the cup refuses to build pressure.

The two main causes for these issues are that the white O-ring in the cover is damaged, or that your Graco Flexliner cups are worn, allowing air to leak out.

Another simple fix once you understand the common problems.

  • If the white o-ring is broken, cracked, or damaged, remove it and replace it with a new one.
  • If your Flexliner cups are worn or damaged, it is time to replace them. You can buy a pack of 3 or 25 to have plenty on hand when needed.
  • As a secondary check, you can also ensure you have the right spray tip for the paint type. If you don't  use right spray tip, you can use paint thinner in the wet cup to make a more compatible solvent.

Output Low On Down Stroke Or On Up Stroke

When you find that the output is low on either the down or upstroke (or both), it can be a few different reasons.

The most likely causes are an open or worn intake valve, pressure transducer, piston valve, pressure control knob or packings. It could also be that you are using a high-viscosity fluid. Check pressure control for smooth operation. Replace build pressure control if necessary.

When you find that one of these issues is the problem, you can resolve them in just a few minutes.

  • If your intake valve is worn or open, access the motor cover to expose the valve and clear, clean, or service the intake valve itself.
  • If your fluid has a high viscosity, follow the instructions in the pump manual and adjust your air intake spacers[1].
  • For issues with the piston valve and packings, simply switch the unit off, clear out the piston valve and replace packings.
Note that these are the same causes for an erratic accelerated speed symptom. If your sprayer is experiencing this issue, check the solutions above.

Runs Sluggishly

If you ever find that your Graco airless sprayer is running sluggishly, the most likely cause is possible icing.

  • To fix an icing issue, you must first switch the pump and then open the de-ice control. The manual will have step-by-step instructions to follow to ensure a proper de-icing procedure.[2]

Cycles Or Fails To Hold Pressure At All

Should your Graco sprayer ever cycle while not actively spraying, or you find that it fails to hold any air pressure between spray lines, it is most likely the seals or check valves that are worn.

The check valve helps build and maintain pressure in the spray cup that pushes the paint to the nozzle.

If the valve or its seals begin to wear down, they won't be strong enough to maintain that pressure. This is a simple fix.

  • Unscrew the black valve and replace it with a new one. These parts wear out with use so it is always a good idea to have a replacement on hand.

Multiple Issues With The Same Solution

Oftentimes diagnosis is made more difficult because multiple causes end with the same symptom. In this section, we reverse the formula and pose the fix and present all possible causes for it.

The solutions can be repair, replacement, adjusting parts, or making a switch to a different paint.

Your spray gun, spray tip, spray tip size, and pump are all common pain point areas. However, larger problems can present from internal parts like the pump, ball seats, motor stops, or trigger mechanisms.

Always check your spray gun manual for disassembly instructions and proper cleaning intervals. Inspect your unit regularly and test the spray pattern before you replace any part.

When you're all ready to paint but you can't engage the trigger, you may have the trigger lock in operation. You can disengage this by rotating the trigger lock. If the unit isn't frozen stuck, it could point toward hardened paint, which would need cleaning.

If you're using an extension cord, check it's not too long and is of a heavy enough gauge for the unit. Replace with a correct, grounded extension cord. For either of these faults, your unit will need to be serviced by an approved retailer or service center.

Disassemble Paint Sprayer

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Incorrect Fluid Pressure at Graco Spray Gun

This symptom's solution is to adjust the air pressure up or down or to check for a worn spray tip.

Depending on the viscosity of your fluid and the number of hours on your spray tip, both present simple solutions. Left untreated, though, it can cause the following problems.

  •  Poor Finish Or Irregular Spraying Pattern
  • Motor Stuck At Top Or Bottom Stroke Of Piston
  • Built-In Air inlet valve Gauge Reads Zero "0". Pour small amount of liquid in inlet valve to prime.
  • Runaway Error Code Displayed, Pump Running Faster Than Set Runaway Limit
  • Air Pressure Is Set Below 1.4 Bar (20 Psi)
  • Poppet Pin Seat Has Debris Or Is Damaged On Top Poppet Valve
  • Binding/Sticking Of Air Valve Cup/Carriage, Or Piston Close Valve
  • Binding/Sticking Spring Loaded Detent

Worn Or Damaged Part (Motor Piston O-Ring, Air Valve Cup, Valve Plate Seal, Flat Gasket)

Worn parts are meant to be replaced. After constant use, seals, o-rings, and valves will break down, wear out or become damaged. While this is normal, it can cause a host of problems.

Double-check your seals, o-rings, and valves before every use. Replace as needed before you find symptoms like these:

  • Air Blowing Out Rear Main Motor Exhaust
  • Air Continuously Exhausting Around Motor Shaft
  • Motor Runs Below 0.68 Bar (10 Psi) Air Input Pressure
  • Air Pressure Varies 0.34 - 0.68 Bar (5-10 Psi) From Set Point Or Air Pressure Jumps To Line Input Pressure From Set Point
  • Air Continuously Exhausting Around Motor Shaft
  • Motor Runs Below 0.68 Bar (10 Psi) Air Input Pressure

Common Graco Airless Paint Sprayer Questions

Are Graco airless sprayers any good?

Graco airless sprayers are popular, but like all airless sprayers, they can have issues due to the complexity of the machine and materials used.

Can Graco paint sprayers work without problems?

Graco paint sprayers can work without problems if properly maintained, cleaned, and worn parts are replaced in time.

Do you need to thin paint for Graco airless sprayers?

Thinning paint for Graco airless sprayers may be necessary if the viscosity is too high for the air pressure supply and paint spray tip on the spray gun, but not always required if within range.

How do you fix a Graco paint sprayer that wasn’t cleaned?

To fix a Graco paint sprayer that wasn't cleaned, you need to completely disassemble and thoroughly clean it using warm water, mineral spirits, clean cloths, and soft bristled brushes. This includes cleaning all parts, seals, rings, valves, hoses, lines, cups and screens.

What is the typical warranty on a Graco sprayer?

According to the Graco Standard Warranty page:

“With the exception of any special, extended, or limited warranty published by Graco, Graco will, for a period of twelve months from the date of sale, repair or replace any part of the equipment determined by Graco to be defective.”[3]


Graco airless sprayers are among the most popular and widely used in both residential and commercial applications.

They are made of high-quality and easy-to-maintain parts but still require general maintenance.

Over time issues with your Graco airless sprayer will occur, as with any paint spray gun type or brand.

Using the guide above, you should be able to determine the root issue and find a simple solution to your problem.