How to Bleed a Hydraulic Jack? | Car Jack Maintenance Guide

Are you a mechanic or car enthusiasts? If yes, a hydraulic jack is your most essential tool. It helps in lifting heavy loads with the help of a hydraulic cylinder. Thus, a faulty hydraulic jack decreases your work efficiency a lot and you need to know how to bleed a hydraulic jack.

For the hydraulic jack to be in the best working condition, you need to purchase the best car jack and maintain it regularly. Regular bleeding can help in the maintenance of the hydraulic jack. Moreover, filling fresh oil in the jack also keeps it functioning. If you have never done bleeding or oil refilling, it's nothing to worry about.

Keep reading to find out how to bleed a hydraulic jack. Besides, you'll also learn how to fill a hydraulic floor jack with oil.

How to bleed a hydraulic jack?

Is your hydraulic jack consistently losing height? Well, most probably, it's getting air within the reservoir, leading to sudden jack failure. As a result, it can damage both you and your vehicle.

But as you know

"An ounce of prevention is worth a pound of cure."

So, it's better to take preventive measures before facing the jack failure. Regular bleeding of the floor jack can help you get rid of this issue.

You might be wondering how you would know your hydraulic jack needs bleeding. Well, you can identify it quickly with two symptoms.

• Firstly, whenever you use the jack, there will be some spongy feel.
• Secondly, your hydraulic jack won't lift the loads and will start losing height.

If both these symptoms are there, bleeding the floor jack becomes essential. Follow all these steps to learn how to bleed a hydraulic jack.

Things you need:

1. Flathead screwdriver or star screwdriver
2. Hydraulic fluid (never use any other type of fluid. Otherwise, the floor jack will erode and become less durable.)
3. Instructional manual of your floor jack

Step 1: Remove the jack.

Firstly, check if the hydraulic jack is attached to the engine hoist. If yes, remove it.

Step 2: Make the floor jack ready for bleeding.

Is your hydraulic jack ready for bleeding? If not, get it ready first.

• Firstly, remove any load from the hydraulic jack.
• Then, place it on the flat surface.
• Finally, clean the floor jack with a damp cloth.

Step 3: Extend the ram piston.

In the next step, prop your floor jack until its ram piston is in a fully extended position. Ram piston is at the place that comes in contact with the object to be lifted.

Step 4: Release the pressure.

After extending the ram piston, release the valve pressure of the jack. You can do it by following the steps below:

• Firstly, locate the bleed valve. It's usually present at the jack bottom.
• Turn the jack handle in an anticlockwise direction.
• Keep rotating till the ram is to the lowest position.

Step 5: Open the filler plug of the jack.

Most importantly, you need to locate the filler plug first. It's primarily present in the main body of the jack. But, it looks pretty similar to two other check valves.

So, make sure you're not confused the filler plug with the check valves. You can use the instruction manual to know about the precise location of the filler plug.

After finding the filler plug, attach the flathead screwdriver with it. Then, rotate the screwdriver in the anticlockwise direction to open the plug.

At this point, you'll hear a sound of hiss, which is probably the sound of air. This sound indicates that all the air from the hydraulic jack has escaped.

Step 6: Close the release valve.

After the hissing sound stops, it's time to close the release valve.

• Attach the filler plug to the jack.
• Turn the jack handle clockwise to close the release valve.
• Repeat the whole process until there is no hissing sound.
• No hissing sound means no air. It means the hydraulic jack is safe to use now.

So, these were the steps to learn how to bleed air out of the hydraulic system. Now it's time to learn how to fill a hydraulic bottle jack or floor jack.

How to fill a hydraulic floor jack with oil?

Does the oil from your jack is leaking out? If yes, you need to figure out the problem instantly and go for bottle jack repairs. However, if all is good, you should refill the hydraulic jack with oil to make better the floor jack.

After bleeding the jack, let's look at all the steps to learn how to fill a hydraulic floor jack with oil.

Step 1: Prepare the jack for oil refilling.

• Adjust the jack to the lowest position.
• Locate the oil filler plug and remove it.
• Open the fluid release valve by turning it anticlockwise.

Step 2: Drain the old oil.

• The next step is to drain the old oil from the jack so that you can fill it with fresh oil.
• Put the jack on one side to drain the old oil from it.
• To drain the residual oil, turn the jack upside down.

Step 3: Fill the jack with fresh oil.

• To fill the fresh hydraulic fluid, place the jack again in the upright position.
• Close the oil release valve.
• Now, pour the new oil into the hydraulic jack with the help of a funnel. Make sure you're using the correct amount of hydraulic fluid according to the manual.
• Wipe the extra oil with the help of a cloth. You can also use an oily rag to make the device rust-free.

Step 4: Release air from the hydraulic jack.

• Once you have filled the hydraulic fluid into the jack, release the air from it using the procedure mentioned above.
• Recheck the oil level. If it's necessary to add more oil, add it.
• In the last, replace the filler plug, and your hydraulic jack is ready to work again. Check by doing up and down the jack.

Final thoughts..!!!

Finally, you have gone through all the steps of how to bleed a hydraulic jack. If your hydraulic jack is not getting the load to the expected height, follow all these steps to make it functional again. Besides bleeding, maintaining the oil level in the jack also keeps it in good working conditions. So, don't forget to check the oil level of your hydraulic jack.