Removing piston rings

I have to remove some piston rings from their groves in aluminium motorcycle pistons. They are stuck fast. Can anyone suggest a method that will not damage the pistons. Thanks

Hello Maurice,

In the past I have removed tight rings by first sottening gummy deposits with paraffin. Once you can get some movement on the ring it is just a question of working that freedom around the ring groove until you have been right round.

Then you can begin to push the rings around in their grooves using a pusher of some sort from the ring gap. It will get easier and easier as the carbon breaks up and can be 'flushed' out with the paraffin. Finally they can be removed over a sleeve of shimming to ease them over the head of the piston. Start from the top compression ring and work down.

With luck that avoids breakage; the shimming protects the rest of the piston during removal. The sleeve can be made from anything thin section, a tinned fruit can might suffice, avoid those with ribbing.

Regards

Brian

Dunk the pistons in boiling soapy water, they usually come loose after a few boils, pistons expand far more than the rings. If they are really stuck in with oil varnish you could try an overnight soak in acetone or some such solvent, then try the boiling water.

Phil

UK

Thanks for the suggestions gents. The boiling water sounds promising, I shall try this shortly. Thanks again.

Regards

Maurice

Depends if you want to save the rings, boiling with a touch of washing powder is good. If you are fitting new rings keep an old one to clean out the grooves.

Let the wife go shopping then nip inside and bang the piston into dishwaher...iff you dont have a dishwasher like myself then small saucepan with engine oil and let it simmer for 15 mins on cooker. When the wife comes back from shops soaking wet and laden down with 6 plastic bags full of food just make sure your not around

Get them (the pistons) good and hot, and then drop them in a bucket of paraffin, let them soak over night they should free off, always works for me. Might need a second heating and dunking.

Mark P.

We use a bucket of diesel to remove stuck fast items. Usually works if you soak them for a couple of days, and you can stand the stink!

Bri

Thanks again for all the suggestions gents. The hot soapy water seems to be working.

Regards

Maurice