I Need to Replace My Yanmar Tractor Head Gasket

We want to help you replace your Yanmar tractor head gasket.

If you do not feel that you understand these steps, or can perform them safely, consult your tractor dealer or local mechanic. And as always check your owner’s manual to verify that you are following the proper steps according to your tractor’s make and model.

Replacing a head gasket may seem intimidating.

No need to worry. If you are willing to put in a little blood, sweat, and tears (and get your hands a bit dirty) --- we are going to get you through the entire process. AND save you a whole lot of money.

REMOVAL

Time to get started…

1. Clean the engine. Make sure the upper portion around the head is as clean as possible.

2. Take pictures of the engine as you disassemble it. This will help you keep track of what goes where.

3. Drain the water from your radiator into a suitable container.

4. Remove the water pump and muffler. While it is not necessary --- it will make the head easier to maneuver.

5. Remove anything attaching the head of the tractor or engine. This includes radiator hoses, fuel injector lines, oil lines, and the wire to the temperature switch.

6. Remove the valve cover.

7. Remove the pushrods and rocker arms. Keep the parts in order so they go back to the same place. TIP: Poke holes in a cardboard box and push the pushrods into the holes to keep them in order.

8. Remove the head nuts or head bolts, depending on your model.

9. Lift the head off. Make sure all the bolts are removed. If it feels stuck --- evenly, and gently pry the head up. Do not pry anywhere near the sealing surface of the head gasket.

10. Dry off the spilled coolant. Put rags or paper towels into the holes on the block to prevent pieces of the head gasket from getting inside. (This includes the water ports, crankcase, and oil ports.)

11. Remove the head gasket.

12. Scrape off any remains from the gasket or any sealer that was used on the block and head. Use a razor blade, gasket scraper, and carburetor cleaner to get everything smooth and clean. Be careful not to scratch the sealing surfaces of the head or block.

13. Inspect the head closely for cracks. Use a feeler gauge and a straight edge to check the block and head to make sure they are flat.

14. Run a tap down each of the head bolt holes to make sure they are clean and free of debris. This will give you a more accurate head bolt torque. A dirty thread can lessen the clamping force of a bolt by as much as 50%.

15. Blow out the head bolt holes with compressed air. This will ensure there is not any liquid, dirt, or head gasket remains in any of the holes. This will also keep the bolts from bottoming out before they are fully tightened.

16. Remove the paper towels or rags from the holes in the block. Double-check that they are all out.

Great news! You are halfway there.

REPLACEMENT

Now it is time to put it all back together.