Seized piston

What are the different methods you use to clear a piston from a cylinder on a seized engine? Does it matter what kind of seizure it is (overuse/excessive RPM, lack of oil, overheat, sat idle for decades, weather exposure, etc.) as to how you approach freeing the piston? Seems there are a lot of ways to skin this cat - hydraulic pressure, burning fluids in the cylinder, soaking for weeks with fluids, simple brute force. Seems to me that a mechanical seizure (overheat, burning an engine up - I realize that it is not truly welded together) would require a different approach than a nonuse seizure. Which is the worse type of seizure, in your opinion? Do you always overbore or replace the sleeves? How often are cranks and rods ruined in these seizures?

As you say, there are a lot of methods to free a stuck or seized engine.

Stuck and seized are different terms. Stuck is usually less destructive if caught in time. Seized is almost always not going to be usable without disassembling and correcting the problem.

The first thing to do is evaluate the situation. An engine that sat for years and is stuck with condensation rust, or even an engine that sat for a relatively short time with water in the cylinders, either from a head gasket leak or from an external source, can sometimes be freed with soaking with penetrant and bumping the starter.

But an engine that sat with liquid water in the cylinders for years likely will not free up, and if it does, real good chance the rings will be stuck and the cylinders pitted to the point it will not be practical to use.

If it won't break loose without a real fight, might as well take it apart and see what needs to be done. If it has sleeves, usually easier to just pull the sleeve with the piston in it and replace both. If no sleeve, a block of wood whittled to fit, and a big hammer (after the rod is disconnected) will usually get it broke loose, then drive it out from underneath. At this point you're not trying to save the piston unless it's something rare.

A seized engine will generally need to come completely apart to inspect each cpmponent and clean out the fine shrapnel in the oil galleys.

Rods are not usually ruined, but can be damaged. They can be reconditioned if not beyond repair.

Well Said. Jim

Is the cycl rusted and does it have a sleeve like other post says if it is sleeved press sleeve and piston out together. If no sleeve sand the walls to get all the rust off so when you can get the piston to move it can be pushed out. what position is the piston all the way down

My JD 420 was stuck from water getting into exhaust. Head was off when I got it. One piston was up. Plumbed an external 20 gal propane into bottom of the block, filled the tank/block with water. Put heat to propane tank til everything was boiling. Let cool and repeat.
Then drilled a crosspiece to fit head bolts over center of piston with steel blocking under cross piece. Tightened bolts and piston moved. After that used starter.

It is tough to do anything from under the tractor. I tried pushing sleeves and pistons out from the bottom with a hydraulic jack and a rod, just lifted the front of the tractor. Finally removed engine flipped it on its top and a couple wacks with a oak block and 6lb sledge had sleeve and piston out. Mine was really stuck from water in two of the cylinders. Good luck with whatever you try. Then comes the hard decisions, how much money do I want to throw at this project, which is where I am now. gobble

Many years ago I had a badly stuck M Farmall that had been outside with no cap on the exhaust. After pulling the head I tried about every method to free it up. Got 3 of 4 loose and useable. No. 1 would not budge. It finally came out....after I took a 1/2 inch drill bit and tore that thing to bits. The sleeve came out broken. A new sleeve and a used piston and it ran fine. There was no way I could have used the rings of the other three, too much of a mess. After loosening a stuck engine you will be miles ahead to re-ring it if the pistons are okay. Your mileage may vary.

Dunno what you are considering, but unless planning to run a "hack job" engine without correctly repairing it, unless it's unusual or rare and means something to you, at today's parts and machine shop prices it would be better to "pass" and find a running version, just MHO.

Are you talking about a rusted ring due to sitting, or a seized piston due to heat?

Take head off pour half gas half tranny fluid take rod caps off and light it walk away till it?s done burning take block and hit piston with sledge and it usually comes loose