How to Install a Freeze Plug

If you notice green fluid leaking from the sides of your engine, it is time to replace the freeze plug. These can rot or even pop out entirely over time. As soon as you notice this problem, you need to replace it immediately. Freeze plugs are meant to pop out if water freezes inside your engine block. Antifreeze prevents this from happening. The problem is that they can rust over time if the proper mix of water and antifreeze is not used. To replace a plug is actually a simple procedure. Being located on the side of the engine block above the transmission makes them pretty easy to reach. Doing this job will not only save the life of your engine, but it will also save you a lot of money.

Tools and Materials Needed:

  • Freeze plug
  • Antifreeze
  • Radiator pressure tester
  • Flashlight
  • Ball peen hammer
  • Needle nose pliers
  • Punch
  • Socket set and ratchet
  • Drain pan
  • Thread sealant
  • Waterproof gloves
  • Safety glasses
  • Closed toed shoes

Step 1 – Shut off Electricity

Disconnect the negative cable from the battery. This will stop the electrical flow to the engine.

Step 2 – Pressurized Tester

When the pressurized tester is hooked up, you will be able to see if the freeze plug is leaking. The pressure will force any liquids out from around the plug.

Step 3 – Drain the Radiator

Remove the drain plug in the radiator or remove the radiator line to drain the radiator. Have your drain pan ready. Do not put the plug back in or reconnect the line at this time.

Step 4 – Freeze Plug Removal

Place the punch on the freeze plug and hit it with the hammer. You want to strike the plug without damaging the area around it. Any damage will soon see leakage. Use the needle nose pliers to assist removing the plug from the block. Have your drain pan ready because there will be fluid to catch once the plug is out.

Step 5 – Insert New Plug

Apply the recommended amount of thread sealant to the new freeze plug. This will help strengthen the seal. Place the new plug into the block and tap in with the hammer. Again, be careful not to damage the area around the plug or the cylinder. Some plugs require the use of a socket and ratchet. Install the freeze plug according to the manufacturer’s directions.

Step 6 – Fill Radiator

Insert the drain plug on the radiator or reconnect the radiator line. Fill the radiator with the amount of coolant specified in the owner’s manual. Make sure all connections are tight. Also, wipe up any fluid spilled on the block or radiator.

Step 7 – Test the Pressure

Now you will require to use the pressurized tester. Use it to see if there are any leaks in the radiator, connections, or the new freeze plug.

Step 8 – Connect Cable

Connect the negative cable back to the battery and start the engine. While the engine is running, check for leaks. If there are not leaks and everything is working well, you have completed the task of installing a new freeze plug.