How to Clean Piston Rings

Piston rings are an important part of the engine, as they help seal the combustion chamber for proper detonation. Engine rebuilding is never complete without cleaning the piston rings. Carbon buildup, soot and extreme temperatures will lessen the effectiveness of the piston rings with regards to providing a perfect seal inside the engine.

Faulty piston rings can be the cause of pre detonation or loose combustion. Examine the piston rings carefully and replace them when needed. Race mechanics and engine builders make it a habit to replace the piston ring every time the engine is overhauled.

Materials Needed:

  • Carburetor cleaner, lacquer thinner or kerosene (any will do)
  • Piston ring expander tool
  • Small plastic basin 
  • Cotton rag or terry cloth towel

Step 1 – Remove the Piston Rings

Remove all three piston rings using a piston ring expander tool to prevent damage. Piston rings comprise of the compression ring, the expansion ring and the oil seal ring. Remove all three rings using a piston ring expander tool to prevent damage. Place the ends of the tool in between the ring gap and squeeze the handle carefully to expand the rings. Slip the rings off the piston.

Step 2 – Immerse the Piston Rings

Fill a small plastic basin with the right amount of carburetor cleaner, lacquer thinner or any other engine solvent. The amount of cleaner should be enough to submerge all three rings to thoroughly remove carbon and gunk. Let it soak for 24 hours.

Step 3 – Dry the Piston Rings

Remove the piston rings from the solution and let them dry by placing the rings on a clean cotton towel. Wipe the rings carefully to remove any excess solvent and dirt. It would be best to clean the pistons first before attaching the piston rings. 

Remember to install the oil seal ring first before the expansion and compression ring. Take care not to inhale the fumes of engine solvents, as this may prove harmful to your health.