28 Mar Tech Tip Tuesday: How to repair or replace the manifold block on a 3.5 or 4-inch stabilization leg
If a seal fails on the manifold block of your stabilization leg, it doesn’t mean you have to purchase a replacement stabilization leg.
All Power-Packer stabilization legs have serviceable manifold blocks, which decreases your repair costs and minimizes machine downtime. Here’s the correct procedure for repairing or replacing the manifold block on a 3.5 or 4-inch stabilization leg:
- First, make sure no weight is being supported by the stabilization legs. Extend the legs slightly from the full retract position to relieve any internal pressure. Mark each hose so you know which port it connects to, then disconnect the hoses from the leg. It is now safe to remove the stabilization leg from your equipment.
- Second, ensure there is no residual pressure in the leg by slightly cracking the pilot-operated check or dual counterbalance valves. This is a very small movement, likely only a quarter or half turn. If there is pressure behind the valves, you will see oil spill out. If this happens, allow the pressure to bleed off, then open the valve another quarter turn to ensure there is no residual pressure.
- Third, remove the lock valve from the leg by turning it counterclockwise with a strap or pipe wrench. The index locking bolt will keep the rod from turning during removal. If you only need to repair the lock valve, you can safely remove it while the leg is still on your equipment, but only if you have a minimum 2-inch clearance above the valve.
- Note: If the leg is on the equipment during service, removing the manifold will allow the shoe to drop to the ground. We recommend extending the leg so it’s just slightly above the ground or supporting the leg prior to removing the manifold.
- Now, remove the O-rings and back-up washers from the piston rod. Replace them with new O-rings and washers, being careful not to roll the O-ring or scratch it when pulling it over the threads on the piston rod.
- Use clean hydraulic oil to lubricate the threads on the inside of the manifold block.
- In a clockwise motion, screw the replacement manifold onto the rod end until it’s finger tight.
- Use the strap wrench to tighten the manifold until it’s firmly seated.
- If the manifold ports are facing in the wrong direction, loosen the index locking bolt enough to allow the manifold to rotate. This will let you to orient the hose fittings in the correct location.
- Tighten the index locking bolt, torque it to 18-24 foot pounds, and reconnect the hoses.
- Complete the fill and bleed procedure.
As you disassemble and reassemble a stabilization leg, it’s very important to keep all parts clean to prevent any damage. Questions about how to repair a 3.5 or 4-inch manifold block on a stabilization leg? Contact our Customer Service team at firstname.lastname@example.org for more information.
Preventative maintenance will ensure the life of your hydraulic system. For routine maintenance tips, check out our February Tech Tip.
Note that these processes apply only to Power-Packer products manufactured in North America.