Expert: Vern Bullock - 8/20/2008

Question
I need to replace the freeze plugs, how do I do this?

Answer
Hi John:

Freeze plugs are normally something you change at overhaul time when the block is stripped, it has been through the acid bath, and the core is clean. So, if you don't have the tools and equipment to do this, consider a mechanic shop.

However, if you can access your freeze plugs, here is how you change them...

Things You’ll Need:
- New freeze plug
- Dremmel Tool
- Flat head screw driver
- Hammer
- Needle Nose pliers
- Socket

Step1: You need to locate the freeze plug that is leaking. Put your car on jack stands or a lift. Add water (not anti-freeze) and while laying under the car, watch for where the dripping is coming from. Freeze plugs are small ~1.5" dish like plugs on the bottom edge of the engine, and cylinder heads.

Step2: Once you find which plug is leaking, drain the coolant system. This makes it a lot easier and cleaner to fix the plug. Wait till the plug is not dripping anymore.

Step3: Get the dremmel tool, and put a cutoff bit on it. you'll need to cut across the edge (side wall of the plug). You'll be able to feel when you cut through it, don't cut the block.

Step4: After you have cut a line through the freeze plug, take the flat head screw driver, and place the tip in the cut you made. Angle the screw driver so the tip is against the plug, not the block. Tap the screw driver with the hammer and it should start rotating the freeze plug. keep tapping till you get the freeze plug sideways in the block.

Step5: Grab the plug with the pliers and pull it out. it should come right out now.

Step6: To put the new plug in, line it up with the hole, and using a socket that just fits the inside of the plug, use the hammer and tap it into place. Make sure to tap it in straight.

Step7: Once the freeze plug is in, refill the coolant system with water, and start the vehicle. Let it warm up and check for leaks. If there aren't any, drain the water, and refill with anti-freeze/water mix. If there is still a leak find out where it is and repeat these steps.