9 Reasons Your Hydraulic Jack Won’t Pump Up and How to Fix It

When raising a vehicle or heavy load, a hydraulic jack is almost always required.

There are occasions where the jack doesn’t pump up fully.

Knowing the most frequent problems you’ll encounter and understanding how to solve them will go a long way in saving you time and headaches.

This post walks you through a few easy troubleshooting steps to get your hydraulic jack pumping up again.

We’ll discuss possible reasons, such as air in the system or a lack of hydraulic fluid, and offer simple solutions.

1. Low Hydraulic Fluid Level

Keeping the hydraulic fluid level in your hydraulic jack is a big part of keeping your jack in top working order.

To avoid this issue, regularly check the fluid level by unscrewing the oil plug and looking inside the hydraulic reservoir.

This makes sure the fluid is between 3/16 and a quarter inch over the top of the reservoir.

If it is low, top off using the proper hydraulic oil. Leaks would cause fluid loss, so check your jack for drips or wet spots.

To keep your machine running at its best, have a preventative maintenance checklist that includes regularly checking fluid levels.

Hydraulic systems are a closed loop, so fluid levels should never drop below zero.

By bleeding the jack once a month, you’ll help it operate at peak performance, which means you’ll enjoy a greater lifting capacity.

If your cylinder is still full of air, repeat this process two more times until air is removed from the cylinder.

Completing these steps at least once a month will keep your jack running safely and efficiently.

2. Air in the Hydraulic System

Bleeding a hydraulic jack system prevents the air from getting trapped and helps it lift more efficiently.

When air infiltrates the system, it prevents the jack from working properly.

First, make sure you open the release valve all the way before lowering the jack. This action serves to purge any air within.

If the jack shows signs of jerky operation, that’s a sign that air is in the system, and it needs to be addressed.

Knowing what performance looks like is essential. If you feel consistent jerking or uneven lifting, air may still be trapped.

By documenting the bleeding procedure, operators are provided a consistent and accurate process every time.

Basic precautions, like marking the position of the valve and timing while removing, serve as a useful guide for future maintenance and repair.

For instance, maintaining a spreadsheet of all bleeds will save time and avoid mistakes by remembering what was previously done.

3. Worn Seals or Gaskets

Worn seals or gaskets can make or break a hydraulic jack’s performance.

Checking these parts for wear and replacing them when needed keeps up pressure.

Choosing a seal kit made exactly for your jack model will provide the best performance seal and the best fit.

Symptoms of worn seals may be leaking fluid and loss of lifting capacity.

If you see oil or air leaking or you feel a spongy ride, chances are your seals are gone.

Abuse and heavy use can lead to quicker wear and tear, but consistent use will give you years of use.

Funnily enough, 80% of jack issues are caused by worn seals.

Developing a maintenance log to monitor seal condition and replacement history will increase dependability.

Seal life is extended with regular maintenance, such as bleeding the system.

Long-lasting quality Some jacks, particularly those incorporated leather piston cups, can last 50 years or more with routine maintenance.

Seal wear is exacerbated by extreme temperature ranges and lack of maintenance.

4. Blocked Hydraulic Lines

Blocked hydraulic lines are a common reason for a hydraulic jack to break.

Check these hydraulic lines for blockages, as mud and other debris can clog lines and stop fluid transmission.

Removing any obstructions allows the jack to function properly.

After cleaning, test the jack to ensure it operates smoothly and correctly.

Low oil levels and air in the system from high travel speeds typically lead to these blockages.

Weak pump seals can also cause this problem.

A spongy feel or trouble in extending are indications of clogs.

Bleeding the system can usually fix this, since 80% of the problems come from air getting trapped in the lines.

To purge lines properly, turn the plug to compress the spring, allowing air to escape while maintaining a seal.

Prior to bleeding, confirm a full oil level and consult your manufacturer for optimal bleeding procedures.

5. Faulty Pump Mechanism

Faulty pump mechanisms in hydraulic jacks always stop them from lifting.

Diagnosing these faults requires checking for debris or dirt clogs, which can significantly impact performance.

For instance, a Michelin 3 1/2 ton trolley jack might only function when the handle extends 4–5 inches beyond its resting point.

Repairing or replacing worn seals, pistons, and similar components can bring pumps back to life, with dried-out components responsible for sluggish or partial pumps.

Regular testing will keep the mechanism running in good working order, preventing around 70% of the problems that specialists such as Metro Hydraulic Jack Company have encountered.

Developing a troubleshooting guide will quickly point to the problem, whether it’s low pressure or the pump is not pumping fast enough.

Faults can be caused by broken valves, making diagnosis difficult.

Addressing these symptoms before they become a problem will keep a jack working properly and safely for longer.

6. Overloaded Jack Capacity

It is a common culprit. Check the weight rating of your hydraulic jack to prevent overload.

Whether using a Jet 22.5 ton jack for house foundation work or a smaller model for car maintenance, know its limits.

Hydraulic jacks have raised heavy loads for years through the use of pressurized hydraulic fluids.

To avoid overloading, it’s important to distribute the weight as evenly as possible on the jack.

Educating users on the importance of following weight capacities is key to ensuring safety and efficiency.

One company, Metro Hydraulic Jack Company, an industry leader in supplying hydraulic industrial parts, strongly advocates for this procedure.

If you have a master list of common items and their weight, it will make judging load limits much easier and more accurate.

For example, the average car weighs around 2 tons, well within the capacity of most standard car jacks.

7. Corroded or Damaged Components

Corrosion damage can really affect a hydraulic jack’s performance.

Routine inspections of all mechanical parts, looking for rust or other damage, is an important step.

Doing so quickly to replace corroded or damaged parts helps maintain safety and prolongs the useful life of the jack.

As one old-school mechanic told me, “You never trust your life to a hydraulic jack—jack stands are life savers.”

Cleaning components with the appropriate solutions ensures jack integrity and promotes jack longevity.

Robust components in older jacks with deep U-cups that are filled with grease can last for decades, occasionally up to 50 years.

Developing a visual reference to identify areas prone to corrosion can be useful.

It is critical to keep in mind that hydraulic systems are closed-loop systems, so fluid is always circulating back, and fluid level should always be sufficient.

For starters, make sure that the oil reservoir is properly filled.

After that, pump the jack handle several times with the jack in the release position.

8. Improper Use or Operation

Failure to properly use or operate a hydraulic jack may result in death or serious injury.

Training users on the proper operation is a critical step in preventing improper use.

In short, making sure that people understand the critical use of jackstands to be safe while working on repairs is key; jackstands save lives.

Providing specific guidance on how to use the jack correctly can avoid 70%+ deaths and injuries due to improper use or operation.

It’s very important to create a safety checklist of do’s and don’ts when operating a jack.

Never take your life for granted by ever trusting a hydraulic jack, no matter what brand or tonnage. Always use jackstands after lifting a load.

Don’t freely turn or twist the plug or valve, because if done incorrectly, performance can be affected.

Regular bleeding of the jack will keep it operating at peak performance. If leaking continues, there is a deeper underlying issue.

9. Temperature Extremes Affecting Performance

Temperature extremes can have a huge impact on a hydraulic jack’s performance.

Droning on Monitoring the operating environment is key to making sure extreme heat or extreme cold isn’t keeping your drone from performing.

Hydraulic systems subjected to extremes such as intense heat or cold will experience catastrophic failure eventually as experienced with those systems.

Keeping hydraulic jacks in a climate controlled space prevents the hydraulic fluid from getting thick.

This makes sure that the jacks work unbelievably smooth.

Using hydraulic oils rated for temperature extremes is key for ensuring the fluid stays consistent and preventing pump issues.

These specialty oils solve problems that conventional oils just can’t.

They do a great job of mitigating risks such as air pollution, including risks from cavitation and aeration.

Here’s a comparison of hydraulic oil performance at different temperatures:

Temperature (°F)	Oil Viscosity (cSt)
32	150
75	68
150	22

Conclusion

Regular care will ensure a hydraulic jack performs its best. Repairing problems such as low fluid or air in the system improves performance.

Worn seals, blocked lines, or a faulty pump require prompt action to keep your equipment running safely and efficiently.

Don’t overload the jack or use it in ways it wasn’t designed for to avoid damaging it.

Avoid extreme temperatures as they will impact performance, so store it smartly.

Frequently Asked Questions

How do I know if my hydraulic jack has low fluid levels?

Inspect the fluid reservoir. If it is lower than the suggested fill level, top it off with hydraulic fluid. If fluid levels are low, the jack will be unable to reach full lift capacity.

What causes air to enter the hydraulic system?

Air can get in from leaks or if you bleed the jack wrong during maintenance. This results in spongy feel and loss of effectiveness as the jack is operated.

How can I identify worn seals or gaskets in my hydraulic jack?

Check for leaks around the pump and/or cylinder. When seals or gaskets become worn they can allow fluid to escape, resulting in lower pressure and the jack’s inability to achieve lift.

What are the signs of blocked hydraulic lines?

If the jack is having difficulty lifting or is slow, you could have clogged lines. A piece of debris or dirt can enter the lines, blocking the flow of fluid.

What should I do if my hydraulic jack has a faulty pump mechanism?

Check the pump for any signs of damage or excessive wear. A defective pump will not produce proper pressure. Proceed with professional repair or replacement as warranted.

How does overloading affect my hydraulic jack’s performance?

Going above the jack’s weight limit puts a lot of stress on the system. This can lead to mechanical failures and serious safety risks. In use, never exceed the weight limits specified by the manufacturer.

Why is regular maintenance crucial for my hydraulic jack?

Proper maintenance will help keep it running smoothly for years to come. It allows you to spot potential problems before they become costly repairs and while ensuring safe operation.