Power Seating Jack Maintenance and Repairs
Power seating jacks operate under intense pressures and in challenging conditions, so equipment failures can have serious consequences. Avoiding those failures is paramount for any post-tensioning crew, and that starts with proper power seating jack maintenance and repairs.
Occasionally, all hydraulic tools need professional service, but repairs can be put off if your operators invest a small amount of time into maintenance. Here, we’ll go over the basic maintenance tasks that will keep your rams in good shape and in the field.
Jack Maintenance is a Matter of Safety
Power seating jacks operate under intense pressure, and if this pressure is not properly contained, it may result in serious and sometimes fatal injury. Early equipment failure is also a likely possibility if your jacks are not properly maintained, but the human cost is obviously a primary concern.
When life-threatening equipment failures do occur, it’s often the result of unregulated pressures building up somewhere in the system. This pressure may compromise either the jack, a coupler or a hose, resulting in sudden, potentially dangerous release of pressure. If the coupler is obstructed or damaged, for example, its threads may be ripped out of the jack, releasing hydraulic fluid at extremely high pressures.
Other potentially life-threatening failures may result if one of the jack’s two ports are obstructed or if the hoses connected to them are suddenly disconnected. If the retract port is restricted, this can also cause a pressure burst while extending the ram.
These are just a few examples. Serious injury may result from inadequate power delivery while under heavy loads, or when the jack is subjected to off-center loads, among other scenarios. Fortunately, almost all dangerous equipment failures can be avoided if the power seating jack is properly operated and maintained.
Basic Jack Maintenance: How to Maintain Power Seating Ram
Most power seating jack maintenance is relatively basic and within the reach of experienced operators. There are times when expert attention is required – we’ll point out some of those signs below – but the majority of preventative maintenance tasks can be easily integrated into your team’s work practices. Some of those tasks include:
- A visual inspection before every job – Before operating the power seating jack, it should be thoroughly inspected for any signs of damage or excessive wear. This inspection should include the jack and cylinder bodies, the jack thread, the cylinder’s piston rods, the couplers, the hoses, all fasteners and any accessories or parts intended for use with the jack.
While inspecting the jack assembly and other components, the point is to identify scoring, pitting, bending, or other signs of damage. If any such signs are spotted, the system may need to be set aside for a full breakdown and internal inspection before the jack may be safely used again. - A thorough cleaning of the ram, couplers and hoses – Contamination is a common, but system-threatening problem that can quickly compromise the jack’s internal components. These contaminants may include water or solids, and they’re usually introduced into the system from the surrounding environment. To prevent dirt and other debris from intruding into the jack, all couplers, fittings, hoses and the jack body itself should be wiped down prior to operation.
- The occasional fluid change – Hydraulic fluid is exhausted fairly quickly, with most power seating jacks needing a change every few hundred hours. Consult the manufacturer’s specifications on when to change out oil and how often to do so. Fluid should also be changed out if there are any signs of contamination present.
- Proper jack storage – When the jack is not in use, proper storage procedures should be implemented. This includes placing the jack in a dry area that is protected from dirt and corrosive vapors. Power seating jacks should be stored with the rod-end facing down. If the jack sits in storage for a year or more between uses, it should be inspected for rust and corrosion before put into operation.
When not in use, all couplers should be protected with dust covers. - Proper operating conditions – Manufacturers engineer their jack and pump systems to manage a rated amount of weight. While this recommendation is a bit lower than the jack’s maximum loading capacity, it’s rarely a good idea to push the jack to this degree. Doing so may overload the jack and cause weight-bearing components to sustain damage and bend. When the jack is not in operation, the rod should be fully retracted to prevent contaminants from entering the system. Check all hoses prior to and during operation, to ensure they aren’t kinked or obstructed in any way. This can cause fluid pressures to climb to unsafe levels in the jack and pump.
- Bleeding air from the system – Air may enter the system through fittings or couplers, or it may be due to a failing seal. Entrapped air will eventually threaten the jack and pump, primarily through cavitation. The first sign of cavitation is a spongy or jerky ram advancement – a product of air’s compressibility.
To restore smooth ram movement and to minimize the likelihood of cavitation, the system should be bled of entrapped air on occasion. This involves connecting a hose to the cylinders, opening the reservoir vent and advancing/retracting the cylinders under minimal (or zero) pressure. This process pushes air out through the reservoir.
Signs That a Power Seating Jack Needs Professional Maintenance or Repairs
Power seating jacks are reliable, rugged machines if well-maintained, but even the most reliable equipment will eventually show signs that more intensive repairs are required. If these signs are present, it’s time to shut the system down and seek an expert opinion from a trusted hydraulic equipment expert:
- The jack is leaking hydraulic fluid – If the jack is leaking hydraulic fluid, it could be due to a loose coupler or hose connection. Those are easy fixes. More troublesome is a potential valve failure, like a relief valve failure. If hydraulic fluid continues to leak after the connections and couplers are tightened, the system will need a full breakdown to look for any seal or valve failures.
- There’s feedback in the jack’s handle – If the gripper handle kicks back during operation, this can pose a hazardous situation for the operator. Handle feedback is often the result of a bad valve – such as a ball valve that won’t seat properly. The system will need to be cracked open to verify the condition of valves and ensure fluid is not flowing back into the reservoir during operation.
- The jack’s fluids are milky or contain noticeable sediment – If the pump’s fluid is opaque or if sediment is floating inside of it, this a clear sign of contamination. The contamination may have been introduced from the environment – dirt or water – or it may be due to internal wear or rust. Whatever the source, fluid contamination can point to a host of problems with the jack – and it can cause many more issues if it isn’t addressed quickly.
- The jack cannot maintain loading – If the jack is over or under tensioning strand, it could be due to inconsistent pressure application. This could be due to internal or external leaking, low oil levels, or trapped air, but sometimes it’s due to a rod or seal failure inside the cylinders. If so, a full breakdown and inspection will be needed to identify the faulty part.
Trust a Hydraulic Tool Specialist with Power Seating Jack Maintenance and Repairs
Hydraulic maintenance – and especially repairs – should only be handled by someone who knows how to do it safely and thoroughly. Otherwise, severe injury and equipment damage may occur.
If your power seating jacks haven’t received a detailed inspection in months, if their performance has slipped, or if signs of damage are apparent, it’s time to call in the hydraulic expert. A trusted hydraulic power specialist can perform a full system breakdown and diagnose which components require repair or replacement, which is invaluable in keeping your crew safe and productive.