HERO 300S Legend - User Manual

Questions and Answers

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Wesley McintoshAug 14, 2025
Why HERO Paint Sprayer electric motor won't start?
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  Jean MillerAug 14, 2025
  The electric motor of your HERO Paint Sprayer might not start due to several reasons: - The unit is unplugged or the building circuit fuse is blown. In this case, check, replace, or reset the fuse. - The pump is under pressure. Reduce the pressure setting by turning the pressure control knob counter-clockwise and trigger the gun to relieve pressure. - The extension cord is too light or too long. Replace it with the correct cord. If the distance is greater than 100 feet, obtain and install an extra length of H.E.R.O. airless spray hose. - The unit's thermal overload switch has opened. Determine and correct the cause of overheating.
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Barbara FoxAug 17, 2025
What to do if HERO 300S Legend has no pressure and blue hydraulic fluid in paint?
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  Kristen GrantAug 17, 2025
  If your HERO Paint Sprayer shows no pressure and you find blue hydraulic fluid in the paint, it indicates that the diaphragm is broken. Replace it with a complete diaphragm. Note that if paint has contaminated the hydraulic side of the pump, the entire hydraulic system must be cleaned and flushed, including removing and cleaning the hydraulic tank screen. Refill only with genuine H.E.R.O. LVO hydraulic fluid. Also, if lacquer has contaminated the hydraulic system, the piston seal must be changed in addition to flushing the system.
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Michelle NielsenAug 21, 2025
What to do if HERO 300S Legend Paint Sprayer fluid being sprayed out of tip pulsates?
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  hancockelizabethAug 21, 2025
  If the fluid being sprayed out of the tip of your HERO Paint Sprayer pulsates and the spray hose continues to move vigorously when the gun trigger is closed, it could be due to: - The outgo valve being assembled incorrectly. Remove the outgo valve and reassemble it following the instructions. - The outgo valve ball being worn out or jammed. Inspect the outgo ball to ensure it is round and free of nicks or cuts. Also, check for any foreign material jamming the ball and inspect the seat and cage for wear. Replace parts as required.
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Juan MaldonadoAug 25, 2025
Why HERO 300S Legend Paint Sprayer electric motor stalls?
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  nicolepenaAug 25, 2025
  The electric motor of your HERO Paint Sprayer might stall or quit because: - The drive belt is loose. Tighten the drive belts by evenly turning the belt tension bolts on either side of the motor clockwise. Loose belts generally emit loud squealing noises. - The unit primes, builds pressure, but the pump “seizes” or “stops” when the gun is triggered. Tighten loose belts.
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jessicaramosAug 31, 2025
What to do if HERO 300S Legend Paint Sprayer has puddle of oil appearing under sprayer during operation?
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  Daniel CarrilloAug 31, 2025
  If you notice a puddle of oil appearing under your HERO Paint Sprayer during operation: - Examine all hydraulic lines and fittings for cracks, breaks, or looseness. Replace or tighten as required. - The piston seals are worn. Remove and replace the piston seals.
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Paul PageSep 6, 2025
What to do if HERO Paint Sprayer has low static pressure and low spray pressure?
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  Steven ContrerasSep 6, 2025
  If your HERO Paint Sprayer exhibits low static pressure and low spray pressure: - The pressure control valve stem screw is loose. Remove the pressure control knob and inspect the screw for looseness. The screw should be secured to the stem with Loc-Tite. If the screw turns independently of the stem, it must be re-secured. - The pressure control ball and/or seat are worn. Remove the entire pressure control valve from the sprayer. Remove the valve seat, ball, retainer, and spring from the valve. Replace with a pressure control repair kit. Hold the valve body vertical while placing in the spring, followed by the retainer. The retainer should be below the valve body when positioned correctly.
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Karen EstesNov 26, 2025
What to do if HERO 300S Legend has correct static pressure but reduced spraying pressure?
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  Autumn HoffmanNov 26, 2025
  If your HERO Paint Sprayer has correct static pressure but reduced spraying pressure, consider the following: - The spray tip is worn out or too large. Replace it with a new, correct-sized spray tip, not exceeding a .021 tip. - The paint hose is incorrect. Replace the hose with a genuine H.E.R.O. airless spray hose (minimum 50 feet). Steel braided hoses must not be used. - The intake valve seat is worn. Replace the intake seat. - The intake ball is worn. Replace the intake balls when signs of wear, deformation, nicks, or cuts are evident. An out-of-round ball indicates a worn intake seat, and both items should be replaced. - The outgo seat is worn. Replace the seat. - The outgo ball is worn or damaged. Replace the outgo ball. - The prime valve is bypassing. Start the sprayer, and with the...
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Janet TylerDec 3, 2025
What to do if HERO Paint Sprayer has total loss of pressure, diaphragm has no movement?