---
title: LockNLube Pressure Return Valve (PRV) for Cordless Grease Guns – (LNL81300-M-ANZ / LNL81300-D-ANZ / LNL81300-MK-ANZ) Troubleshooting
description: Help
---

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10 February 2026

# LockNLube Pressure Return Valve (PRV) for Cordless Grease Guns – (LNL81300-M-ANZ / LNL81300-D-ANZ / LNL81300-MK-ANZ) Troubleshooting

## An innovative Pressure Return Valve attachment for cordless grease guns that relieves built-up pressure in the grease hose with a twist of a knob.

- **General Design** 
    - Simple, robust valve with return pathway
    - Requires minimal maintenance under normal use
- **Post‑Installation Checks** 
    - Ensure PRV is tightened correctly onto the grease gun using wrench flats
    - Ensure hose is snug on the PRV outlet
    - Thread sealant or Teflon tape may be used if needed, though O‑rings/washers usually seal adequately
- **Pressure Return Not Working** 
    - Verify grease cartridge is not completely full (air space is required for return grease)
    - Ensure PRV knob is fully opened (typically activates within about half a turn)
    - You should feel pressure release when opened correctly
- **Best Practice Tip** 
    - Always open the PRV before attempting to remove the coupler
    - If the coupler feels stuck, stop and relieve pressure using the PRV
- **Leaks Around Knob** 
    - Grease seepage around the knob stem may indicate a worn or damaged O‑ring
    - Contact LockNLube for support; replacement O‑ring or unit may be provided (rare)
- **Cleaning & Corrosion Prevention** 
    - Steel body should be wiped clean after use
    - Dry after exposure to moisture, rain, or caustic greases
    - Do not submerge in water
- **Compatibility Warning** 
    - Use only on specified grease gun models
    - Each PRV variant is sized for specific brands and thread patterns
    - Force‑fitting on unsupported models can cause leaks, damage, and void warranty
- **Lubrication Tip** 
    - Occasionally open the PRV during greasing to allow fresh grease to lubricate internal valve components
- **Routine Inspection** 
    - Check that the knob has not loosened during transport
    - No disassembly required for normal operation
- **Stiff Knob Operation** 
    - May be caused by dried grease internally
    - Cycle the knob open and closed during use to flush fresh grease through
- **Handling** 
    - Avoid dropping the grease gun on the PRV body
    - Treat with the same care as the grease gun itself
    - Designed to last the life of the tool with proper handling

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