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

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1. [Macnaught Group Help](https://kb.macnaughtgroup.com/?hsLang=en-au)
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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) Repair Kits

## 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.

- **Repair Kits** 
    - No dedicated PRV repair or rebuild kits are sold
    - Not intended for user servicing beyond basic checks
- **Failure Resolution** 
    - Typical solution is warranty replacement or unit swap
    - Internal valve sticking or worn knob O‑ring are rare
- **Minor Field Fixes** 
    - Knob is secured with a set screw; retighten if loose
    - Internal O‑rings may be matched with generic equivalents if damaged, though not officially supplied
- **Troubleshooting Before Replacement** 
    - Confirm PRV is installed on a supported grease gun model
    - Ensure return path into the cartridge is not blocked
    - Nearly empty cartridges may have the plunger fully forward, leaving no return space
    - Installing a new cartridge or backing the plunger slightly can restore function
- **When to Contact LockNLube** 
    - Knob spins freely with no pressure relief
    - Knob is jammed and cannot be turned
    - Persistent leaks or failure despite correct installation
- **Summary** 
    - No user maintenance kit required
    - Any non‑trivial issues are handled by the manufacturer
    - Periodic external cleaning is usually all that’s needed

- [Product Applications](https://kb.macnaughtgroup.com/product-applications?hsLang=en-au#main-content)

    - [Grease Equipment](https://kb.macnaughtgroup.com/product-applications?hsLang=en-au#grease-equipment)
    - [Air Equipment](https://kb.macnaughtgroup.com/product-applications?hsLang=en-au#air-equipment)
- [Product Troubleshooting & Maintenance](https://kb.macnaughtgroup.com/product-troubleshooting-maintenance?hsLang=en-au#main-content)

    - [Grease Equipment](https://kb.macnaughtgroup.com/product-troubleshooting-maintenance?hsLang=en-au#grease-equipment)
    - [Air Equipment](https://kb.macnaughtgroup.com/product-troubleshooting-maintenance?hsLang=en-au#air-equipment)
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    - [Grease Equipment](https://kb.macnaughtgroup.com/find-repair-kits?hsLang=en-au#grease-equipment)
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- [Warranty Policy](https://kb.macnaughtgroup.com/warranty-policy?hsLang=en-au#main-content)

    - [Grease Equipment](https://kb.macnaughtgroup.com/warranty-policy?hsLang=en-au#grease-equipment)
    - [Air Equipment](https://kb.macnaughtgroup.com/warranty-policy?hsLang=en-au#air-equipment)