How to Fill a Hydraulic Floor Jack with Oil

Jacks are must needed handy tools for car repairs and maintenance. In some cases, to repair or maintenance your car, you have to go down your car and for this, car need to lift up. To lift up the car, you have to place jacks for your safety.

However, these jacks need maintenance as well. Since it lifts a lot of heavy objects, you need to keep hydraulic fluid levels full.

The oil is as important as the fluids present in the jack to lift things up. That way, your jack can work properly, and you will be safe when working under a car.

Most jacks don’t have oil present in them when you buy them. Also, you will need to fill up the hydraulic floor jack with hydraulic jack oil once in a few years.

Note: Before you proceed to add hydraulic jack oil, you should always check the parts of the jack when filling it up. That way, you can ensure that your jack is safe to use.

6 Steps to Add Oil to a Hydraulic Floor Jack:

How do you troubleshoot a hydraulic jack?

Here are some ways to troubleshoot your hydraulic jack:-

  • Check the weight rating of your jack.
  • Inspect the components of the jack before and after every use.
  • Close the release valve by turning the handle clockwise to test the jack before using it.
  • Check for any trapped air.
  • Check the hydraulic oil level of the jack.

Here are process of refilling a floor jack with Hydraulic Oil:

Step One:  Prepare the Jack For Refilling

The first step that you need to do is to put the jack on a surface that is hard and level. Then you need to loosen the release valve. There are two varieties of release valves that you can find in your floor jack.

You can turn one of them with a flat head screwdriver while the other one can be turned with a special handle. Turn the screw counter-clockwise to release the valve.

Check the user manual if you are having any difficulty finding out the valve.

This step will make the oil flow back to the main reservoir, and the jack will lower completely. That way, you can take out any air from the cylinder. Wipe out the area if you see any oil seeping out of the release valve.

Step Two: Remove Cover Plates

This step is not applicable to everyone. Sometimes your hydraulic jack may have a cover plate that protects the internal mechanism of the jack.

See what kind of screws are holding the plate and find suitable screwdrivers. Most of the time, the manufacturers use Phillips head screws.

Sometimes, the plate may come off easily, or you may have to put in a bit of effort. Once you open it, keep the plate and the screws in a safe place.

Step Three: Find the oil fill plug and open it

You will need to find the oil plug so that you can add oil to the cylinder. In most cases, the oil plug is located near the floor of the hydraulic jack oil reservoir.

In some of the newer versions, it is located at the top of the reservoir. Even so, check the user manual to confirm the position. The plug will be well labeled in most of the jacks, making it easy to find.

You may either need to screw the plug open or ply it. You can use a flat head screwdriver to ply open the cap.

Do not try to open the filler port with force if you want to avoid any damage. If it does not come out easily, you will need to learn the proper way to open it.

After you have located the cap, use any cloth or rag to clean out any oil seepage around the plug. That way, you can make sure that no contamination happens when you are filling up the jack oil.

If you have an older jack, you will see that a lot of dirt and oil has accumulated near the valve in years.

If you cannot clean it manually, you can use a hose or pressure washer to remove all the dirt completely before opening the plug.

Step Four: Check oil levels and fill the reservoir

Once you have opened the oil fill plug, you need to check how much oil is left in them. That way, you can make sure that you don’t fill it up with excess oil.

Use a flashlight and look at the oil levels. If you can see some of the inner cylinders, then you need to add more oil.

To ensure that you do not spill any floor jack oil, use a funnel. You should not use any other oil than hydraulic oil for jack as they are designed for this purpose.

Also, you should use a good quality liquid. Since you will be changing the oil once in a few years, this investment will be profitable.

Step Five: Replace the filler plug

Screw back or push the cap back to replace the filler plug. Use the rag once again to clean up any oil spillage.

An additional tip: Use the oil-soaked rag to rub over the components of the hydraulic floor jack. This will put a coat of oil on the components and protect them from rusting.

Final Step: Close up the plates

After you are done adding oil to the hydraulic floor jack, screw back the cover plates. You can use the rag to rub over the cover plate as well.

And that’s it. You have successfully learned how to fill a small hydraulic jack with oil. We recommend that you check the oil levels once every twelve months. Also, keep an eye for leakages.

How to Maintain Your Floor Jack

If you do some maintenance, your floor jack will provide you good service for many years to come.

Also, regular inspection and maintenance will make sure that the jack works properly and will keep you and your car safe. The maintenance processes are simple and won’t take much time.

Step 1:- Inspect the Components Regularly

Before you use your jack, always check the components of the jack. Look out for loose screws, cracks, or any serious damage. Once you find it, you should repair or replace it as soon as possible.

Also, don’t forget to check for oil leakages.

Step 2:- Clean the Jack

Since jacks operate with hydraulic oil, any exposed grease would be the perfect place for dust and dirt to settle in. Use a clean cloth regularly to clean the surface.

You can also use a lightly oiled cloth to wipe down the surface.

Step 3:- Apply Lubrication

To ensure that all the moving parts of your jack work properly, you should always lubricate them. We recommend that you use grease instead of oil as it remains in place and does not drip.

Step 4:- Store it Properly

You should always release all the pressure in the jack when you are storing it. Not doing that puts stress on the jack’s components and can harm them in the long run. Also, you can save a lot of space by releasing the cylinder.

How to Fix a Floor Jack that Won’t Lift

There may be several reasons why your jack won’t lift. The object you are trying to lift may be heavier than the maximum load capacity of the jack. Or some parts may be damaged.

Here are some things that you can do to fix a floor jack that won’t lift.


If some air is trapped inside the jack, it won’t be able to lift any vehicles. You will need to perform a process called bleeding.

You will need to retract the jack’s release valve completely so that all the trapped air comes out.


Sometimes the release valve becomes too tight, and that is why it cannot lift any vehicles. You should take a look at how tight the valve is and adjust it accordingly.


Some of the parts may be rusty. In some cases, the welds may be damaged as well. In that case, perform a full examination of the jack.

Inspect the ram by turning the jack to its sides and look for damaged or rusted components.


Lack of lubrication might be a big reason for your floor jack to malfunction. You should apply the recommended amount of lubrication on a regular basis. Don’t even think of buying cheaper oils if you want your jack to work properly.


1. How much oil do you put in the jack?

Keep on pouring oil and check the oil levels in between. Stop pouring when the oil level has reached just below the lower rim of the oil fill plug.

2. What kind of oil do you use in a hydraulic floor jack?

Considering all the properties that are required in a hydraulic jack oil, you should use ISO 150 and 8W32 hydraulic jack oil as it meets most of the requirements.

Some use motor oil as a substitute, but we strongly believe you should avoid it and use only the recommended oil.

3. How do you check the oil in a floor jack?

Open the oil fill plug and take a look at the reservoir. You can also use a torch to see things clearly. If the oil level is just below the lower rim, no need to fill it.

4. What if, after filling, my hydraulic jack won’t extend fully with weight on it?

In such a case, check whether the weight of the object exceeds the load capacity of the jack. Also, check if any of the components of the jack is damaged or rusted.

5. Why is my hydraulic jack not working?

Here are some reasons why your jack may be malfunctioning:-

  • The weight of the object is greater than the load capacity of the jack.
  • The hydraulic oil levels are low.
  • Some components are rusted or damaged.
  • The release valve is too tight.


This is everything you need to know About filling a hydraulic floor jack with oil. Once you know the process, you will see that it is pretty easy.

Make sure to maintain the floor jack on a regular basis so that it can serve you for years to come. You even know what to do in case your jack stops lifting any weight.

Make sure that you don’t cut any costs and buy only good-quality oil and lubricants.

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