The Challenge of Grease Blockage in Pivot Pins
Pivot pins in heavy equipment like backhoes and loaders are designed to rotate under load while remaining lubricated. Grease fittings, or zerks, allow for pressurized grease to enter the bushing and coat the pin. However, over time, hardened grease, corrosion, or misaligned bushings can block these passages, preventing lubrication and accelerating wear.
In older machines such as the Case 580B, which has served operators reliably for decades, this issue becomes more common. One operator faced a situation where two pins refused to take grease. While one responded to a combination of solvent soak and high-pressure greasing, the other—located at the bottom of the backhoe yoke—remained stubbornly clogged.
Initial Remedies and Pressure-Based Techniques
The first step in addressing a blocked grease passage is to replace the grease fitting. Zerks can fail internally, and swapping them out is a quick diagnostic move. If the problem persists, applying a penetrating solvent like SeaFoam or PB Blaster into the fitting and letting it soak overnight can soften hardened grease.
Once soaked, using a high-pressure grease gun—preferably pneumatic or battery-powered—can force the blockage out. Operators have reported hearing a “pop” when the grease finally breaks through, indicating success.
Another method involves manipulating the equipment’s geometry to relieve pressure on the pin:
Advanced Tools and Heat Application
If conventional methods fail, specialized tools like the Zerk Zapper can be used. This device threads into the grease port and injects hydraulic fluid under extreme pressure, often clearing stubborn blockages. Some technicians also adapt a porta-power hydraulic pump to the zerk thread for similar results.
Heat is another option. Applying a propane torch or weed burner to the pin area can expand the metal slightly and soften old grease. However, care must be taken not to damage seals or paint. A cutting torch can also be used to blast hot oxygen into the port, vaporizing hardened grease with a “woosh.”
When Removal Becomes Necessary
If all else fails, removing the pin may be unavoidable. In the case of the Case 580B, the operator eventually extracted the pin and discovered the grease passage completely packed with hardened residue. A drill bit was required to clear the blockage. After cleaning, the pin was reinstalled and greased successfully.
This underscores a key point: some blockages cannot be cleared externally. If the bushing has rotated or the grease hole is misaligned, no amount of pressure or heat will help. In such cases, disassembly is the only solution.
Preventive Measures and Maintenance Tips
To avoid future grease failures:
A pin that won’t take grease is more than an inconvenience—it’s a warning sign of potential mechanical failure. By combining pressure manipulation, solvent soaking, heat, and specialized tools, most blockages can be resolved without disassembly. However, when internal alignment or hardened buildup prevents flow, removing the pin may be the only path forward. With regular maintenance and attention to lubrication habits, operators can keep their machines running smoothly for decades.
Pivot pins in heavy equipment like backhoes and loaders are designed to rotate under load while remaining lubricated. Grease fittings, or zerks, allow for pressurized grease to enter the bushing and coat the pin. However, over time, hardened grease, corrosion, or misaligned bushings can block these passages, preventing lubrication and accelerating wear.
In older machines such as the Case 580B, which has served operators reliably for decades, this issue becomes more common. One operator faced a situation where two pins refused to take grease. While one responded to a combination of solvent soak and high-pressure greasing, the other—located at the bottom of the backhoe yoke—remained stubbornly clogged.
Initial Remedies and Pressure-Based Techniques
The first step in addressing a blocked grease passage is to replace the grease fitting. Zerks can fail internally, and swapping them out is a quick diagnostic move. If the problem persists, applying a penetrating solvent like SeaFoam or PB Blaster into the fitting and letting it soak overnight can soften hardened grease.
Once soaked, using a high-pressure grease gun—preferably pneumatic or battery-powered—can force the blockage out. Operators have reported hearing a “pop” when the grease finally breaks through, indicating success.
Another method involves manipulating the equipment’s geometry to relieve pressure on the pin:
- Extend the dipper stick
- Lower the boom onto the bucket
- Curl or open the bucket to shift load angles
- Swing the boom to the side to change stress vectors
Advanced Tools and Heat Application
If conventional methods fail, specialized tools like the Zerk Zapper can be used. This device threads into the grease port and injects hydraulic fluid under extreme pressure, often clearing stubborn blockages. Some technicians also adapt a porta-power hydraulic pump to the zerk thread for similar results.
Heat is another option. Applying a propane torch or weed burner to the pin area can expand the metal slightly and soften old grease. However, care must be taken not to damage seals or paint. A cutting torch can also be used to blast hot oxygen into the port, vaporizing hardened grease with a “woosh.”
When Removal Becomes Necessary
If all else fails, removing the pin may be unavoidable. In the case of the Case 580B, the operator eventually extracted the pin and discovered the grease passage completely packed with hardened residue. A drill bit was required to clear the blockage. After cleaning, the pin was reinstalled and greased successfully.
This underscores a key point: some blockages cannot be cleared externally. If the bushing has rotated or the grease hole is misaligned, no amount of pressure or heat will help. In such cases, disassembly is the only solution.
Preventive Measures and Maintenance Tips
To avoid future grease failures:
- Grease pins daily during active use
- Use high-quality lithium-based grease with anti-seize additives
- Replace zerks annually or when resistance increases
- Clean around fittings before greasing to prevent contamination
- Rotate equipment geometry during greasing to relieve pressure
A pin that won’t take grease is more than an inconvenience—it’s a warning sign of potential mechanical failure. By combining pressure manipulation, solvent soaking, heat, and specialized tools, most blockages can be resolved without disassembly. However, when internal alignment or hardened buildup prevents flow, removing the pin may be the only path forward. With regular maintenance and attention to lubrication habits, operators can keep their machines running smoothly for decades.
