Rebuilding a Leaking Hydraulic Cylinder Rebuilding a Leaking Hydraulic Cylinder

What You'll Need
A rebuild kit for the hydraulic cylinder that is leaking
Wrenches
Screwdrivers
Hammer
Pipe Wrench
Crescent wrench
Socket set
Bench vise
Car jack and jack stands
Plastic container
Old rags or towels

If a hydraulic cylinder in your vehicle is leaking, you will need to rebuild the cylinder with new piston rings and seals in order to stop the leak. Rebuilding a leaking cylinder is not a difficult job, and it is one you can complete in a couple of hours. Therefore, here is a handy step by step guide that will help you do it.

Step 1 - Buy Rebuild Kit for the Cylinder

First, you'll need to buy a rebuild kit for the leaking cylinder. So, visit your favorite local auto parts store or order one online for your particular make and model vehicle. Once you have received the rebuild kit, you can proceed.

Step 2 - Prepare the Vehicle

Disconnect the negative battery cable from the post on the terminal of the battery.

Step 3 - Raise the Vehicle

Use a car jack to jack up your vehicle and then place it on the jack stands.

Step 4 - Remove the Hose and Leaking Cylinder

Disconnect the hose that is attached to the master hydraulic cylinder by removing the screw or nut that holds the clamp or hose clip in place. Then, place the plastic container underneath the cylinder in order to catch any hydraulic fluid that may drain out. Finally, remove the master cylinder by loosening the bolts and nuts that hold it in place.

Step 5 - Open the Cylinder

Once you remove the cylinder, you'll need to open it so that you can install the new rebuild kit. Therefore, place the cylinder in a bench vise, and clamp the vise tightly in order to secure the cylinder. Then, use the pipe wrench to loosen the cap that is located on the bottom of the cylinder. This should be the only part of the cylinder that's threaded, so it should be fairly easy to identify. Loosen the cap completely and pull it off.

Finally, place a socket extension into the hole where the cylinder cap was once mounted. Then, use a hammer to tap on the end of the extension. This will cause the cylinder to expand. You can then fully extend the cylinder by hand.

Step 6 - Replace the Seals

Remove the seals in the cylinder and replace them with the new ones from the rebuild kit.

Step 7 - Replace the Piston Rings

Then, remove and replace the piston rings in the cylinder.

Step 8 - Close the Hydraulic Cylinder

Once you have installed the new components of the cylinder, use your hands to push the cylinder back together. Then, replace the threaded plug removed earlier and tighten it with a wrench.

Step 9 - Re-Install the Cylinder

Reinstall the hydraulic cylinder into its original location and tighten the nuts or bolts that are used to secure it.

Step 10 - Reattach Hose

Reconnect the hydraulic hose back onto the cylinder, and then tighten the clamp or clip that is used to secure it.

Step 11 - Refill with Hydraulic Fluid as Needed

If you need to add hydraulic fluid, remove the fill plug on the cylinder and fill the reservoir to the fill line.

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