break loose siezed piston

[Busmech]

1/3 atf + 2/3 diesel works great as a soak for stuck piston or old rusty chain.

 

[David Y.]

Coke

I had an aircraft mech tell me you could use coke (the soda, not the drug) to break free a rusted piston. He said he poured it in and let it sit overnight.

 

[Jonny Quest]

I had an aircraft mech tell me you could use coke (the soda, not the drug) to break free a rusted piston. He said he poured it in and let it sit overnight.

Coke has carbonic acid and phosphoric acid. Hmmmmmm....

 

[Bill G]

Just like many others have mentioned Kroil and grease. They make a good combo as long as the piston is above the ports. Fill it up with Kroil. If it soaks in you are in the right direction. If not let it sit a month. Add grease pressure and forece the Kroil in. The grease will also move the piston down to the ports. After it hits the ports it gets tougher. If is has a removable head that is easier. I will attach a picture of my grease gun tool and a squirter of Kroil. We buy it by the gallon and use squirt bottles.

Bill