SOLO 425-HD

SOLO 425-HD Backpack Sprayer User Manual

Model: 425-HD

Designed to make even the largest spraying jobs manageable. Unique fluid-driven pump design pressurizes to working pressure with as few as eight to ten strokes. Easily provides consistent pressure when precision application is required.

Important Safety Information

WARNING:

This product produces high pressure. Always follow proper handling and usage instructions to prevent injury. Never point the nozzle at people or animals. Always wear appropriate personal protective equipment when using this product. Never mix chemicals in the tank. Always clean the sprayer after use and dispose of any remaining solution responsibly. Always follow the manufacturer's instructions for proper maintenance and disposal.

Product Overview

SOLO 425-HD Backpack Sprayer, front view

Front view of the SOLO 425-HD Backpack Sprayer, showing the white tank with "SOLO 425-HD HEAVY-DUTY Made in USA" branding, the black lid, pump handle, and spray wand with nozzle.

Key Features:

  • High-performance piston pump for liquid formulation.
  • Adjustable pressure regulator with four settings: 15, 30, 45, 60 psi.
  • Durable professional grade brass adjustable, brass fan, hollow cone, jet stream nozzles.
  • No-drip check valve eliminates nozzle drip after pressure is released.
  • Viton seals in critical locations for superior chemical resistance.
  • Extra large carrying handle with wand retainers for easy portability and storage.
  • Deluxe shoulder straps and waist belt for user comfort.

Setup and Assembly

Before first use, ensure all components are securely attached and properly assembled. Refer to the included diagrams for visual guidance.

  1. Attach Shoulder Straps and Waist Belt: Connect the deluxe shoulder straps and waist belt to the designated attachment points on the sprayer frame. Adjust for a comfortable and secure fit, ensuring the weight is evenly distributed across your back and hips.
  2. Connect Hose and Wand: Securely attach the spray hose to the pump outlet and the spray wand to the hose handle. Ensure all connections are tightened to prevent leaks.
  3. Install Nozzle: Select the desired nozzle (brass adjustable, brass fan, hollow cone, or jet stream) and screw it firmly onto the end of the spray wand.
  4. Inspect Seals: Verify that all seals, especially the Viton seals, are properly seated and free from damage. This ensures superior chemical resistance and prevents leaks.
Person wearing SOLO 425-HD Backpack Sprayer

A person wearing the SOLO 425-HD Backpack Sprayer, demonstrating how the shoulder straps and waist belt distribute weight for user comfort during operation.

Operating Instructions

Follow these steps for safe and effective operation of your SOLO 425-HD Backpack Sprayer.

  1. Prepare Solution: Carefully mix your desired liquid formulation according to its manufacturer's instructions. Never mix chemicals directly in the sprayer tank.
  2. Fill Tank: Unscrew the tank lid and pour the prepared solution into the 4-gallon tank. Do not overfill. Securely fasten the lid.
  3. Pressurize Sprayer: Place the sprayer on your back using the shoulder straps and waist belt. Operate the pump handle with a steady, rhythmic motion. The unique fluid-driven pump design will pressurize the tank to working pressure with as few as eight to ten strokes. Continue pumping until the desired pressure is achieved.
  4. Adjust Pressure (Optional): The adjustable pressure regulator offers four settings: 15, 30, 45, and 60 psi. Adjust the regulator as needed for precision application.
  5. Begin Spraying: Point the nozzle towards the target area and depress the trigger on the spray wand handle. Release the trigger to stop spraying. The no-drip check valve prevents dripping after pressure is released.
  6. Maintain Pressure: Periodically pump the handle during operation to maintain consistent pressure for optimal performance.

Maintenance and Storage

Proper maintenance ensures the longevity and optimal performance of your sprayer.

Troubleshooting

Refer to this section for common issues and their solutions.

ProblemPossible CauseSolution
No pressure or low pressure
  • Tank lid not sealed properly
  • Insufficient pumping
  • Clogged nozzle
  • Worn or damaged pump seals/O-rings
  • Tighten tank lid securely.
  • Pump more vigorously.
  • Clean or replace nozzle.
  • Inspect and replace seals/O-rings.
Leaking from connections
  • Loose connections
  • Damaged O-rings or washers
  • Tighten all hose and wand connections.
  • Inspect and replace any damaged O-rings or washers.
Nozzle dripping after release
  • Faulty no-drip check valve
  • Debris in check valve
  • Clean the check valve.
  • If issue persists, replace the check valve.

Specifications

AttributeDetail
BrandSOLO
Model NameBackpack Sprayer w/ handle
Item Model Number425-HD
Tank Volume4 Gallons
MaterialHDPE, Polyethylene, Steel, Brass
Item Weight11.03 pounds (5.01 Kilograms)
Product Dimensions9.5"W x 21"H
Power SourceManual
Included ComponentsPump, Hose
Maximum Pressure90 PSI (9E+1 Pound per Square Inch)
UPC720343425772

Warranty and Support

SOLO products are manufactured by Solo, Inc. For specific warranty details, please refer to the documentation included with your purchase or visit the official SOLO website.

Protection plans are available for extended coverage. For assistance with product operation, maintenance, or troubleshooting beyond this manual, please contact SOLO customer support. Keep your model number (425-HD) and UPC (720343425772) ready when contacting support.

For more information, you may visit the SOLO Store on Amazon.

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