piston will NOT move... now what?

I did all the soakings of differnt flavors for a month now. I got 5 out of the 6 to move. #5 will not move. It needs to come out one way or another. a piece of 4x4 and a baby sledge didnt move it. I did all the other tricks. blends and such. now whats next? thanks

 

maybe a little heat and some pb blaster might get it moving..
heat it up and after it cools down maybe it will break free.

(heat it..not melt it)

 

loosen the rod a little and move the crank some, then when there is some clearance, whack the top ,or bottom of the piston with a wood block.

 

A good long cold chisel and a BFH will solve your problem.

 

Put the head on, both valves closed. First, try a pressure washer, just ram the nozzle in the plug hole and pull the trigger. If that doesn't do it, find a farmer and borrow a tractor with hydraulics. Adapt the hydraulic hose to the plug hole and give 'er a short blast. It WILL move with a few thou pressure! Careful you don't break something, if another piston is stuck too you can bend a rod. Or put a grease nipple in the adapters and use a grease gun.

 

R U trying to save the pistons? If not then drill several holes across the face in a line. Then try heating around that cylinder evenly, and try tapping around the piston face. If still no go then take a hacksaw blade and cut the wall of the piston via the line of holes drilled in the face, then repeat the heat and tapping. If still no go, then try drilling and tapping two holes (1/4-20) across from the line of holes (near center of piston) about an inch apart. Install studs or screws in the tapped holes, then using a vise grip plier across the two studs or screws, tighten till there is some tension on the studs or screws. Try heating again and tapping.

After all this and still no go? You will probably have to drill more holes in the piston. Good luck.

 

Fabricate a 1/2" plate of steel with mounting holes to match the block deck. Thread a grease nipple into plate. Fill the cylinder with grease and then pump the piston out with a grease gun. Nothing will get damaged this way. Not even the piston.

 

Wash out the oil based products and fill it full of vinegar. Come back in a week. This will attack rust between the ring & bore, as well as the aluminum piston. Even if the rings don't free, the aluminum will be mush after a few weeks. Problem solved.

Don't go nuts with the hammer if they're that stuck. Be patient. Good luck

 

I've had really good luck filling the cylinders with rubbing alcohol

 

same type of thing,but make an adapter for a grease gun to lug into,pump the cylinder full of grease with a grease gun and it will move,fill the cyl. by hand before putting the head back on.

 

this will work.

 

I'm guessing you tried brake fluid. As mentioned try heat and a block of wood.

 

Ever heard of C-4? Worked for me--:O)

 

did all the liquids... and the b f h. didt do vinegar. I dont see how the pressure from a grease gun would push the piston down if a bfh didnt do it. ?? anyway. i did take the rod cap off and gave the crank a turn to make some clearance. wonder if I would place a jack unber the motor with a piece of wood between the jack and a lobe of the crank. jack it up to put steady pressure on it and let it sit that way for a while? I looked up under the piston . around the skirt area it is still dry. nothing has penetrated the bore within a month. do i just need to wait it out? I really dont want to ruin the piston.

 

I just remembered that COKE works good too for loosening rust.

 

did it!

 

now that you have some clearance with the cap loosened, not off, hit it from the top and see if it will move.

 

vinegar or muriatic acid (pool supply store) supposedly works fairly well, just takes some time to penetrate. somebody told me urine works too, i guess because of the mild acid. course, they could have just been trying to get me to piss into my motor. it's a cheap method, though--you can make you own using plain old water.

a few rounds of torch heating and cooling was all i needed on the locked up six i did a while back, just be careful not to melt the piston (obviously)

 

Take this one step further: Use a pneumatic grease gun. Then tap rod with small rapid strokes. Should come loose then.

 

I have done this more than once. Grease is the medium to use. Self lubing and is gentle. The piston will move slowly as per grease gun stroke. Throw the hammers and chisels away. This works well on bike motors also.

 

Muriatic acid works great for removing piston material from cylinder wall after a lock-up but it will take quite a bit to eat a piston.

 

What engine are we talking about exactly? Old Chrysler six? Pistons are still avalable, turn the engine upsidedown with the crank out and beat the underside till the top brakes off. Then you should be able to knock the rest out pretty easy. If you have that much rust the thing is going to need to be bored, maybe sleeved, so what is the point of trying to save one piston.

 

It take a BIG hammer and a LOT of swinging to equal the force of a one ton press.

The grease turns your piston and cylinder into a hydraulic cylinder. A 3.5" diameter bore has an area of 9.62 square inches. Apply 1000 psi from a grease gun and you have 9,620 lbs pressing the piston out. some grease guns claim 10,000 psi, which would be 96,200 lbs of force, or almost 50 tons.

Some times a the shock of a steel hammer moves the metal better in a small area, like when stamping numbers, don't be mislead by that, a press is way more powerful than a hammer.

 

Well said!

 

coke wont work...it might have done a few years back...but i`m sure i was told the formula has changed....my son bought a `stuck` engine to use for his drag beetle ...we tried all the mythological fixes....and in the end we just tore it apart....

 

1000 PSI pumped into a larger cylinder is still 1000 PSI. It doesn't magically multiply

 

I've attached a picture of another method that worked for me. I filled the cylinders with breakfree..http://www.break-free.com/ and used one of our large painting heat lamps to heat the block. Every morning I would turn the lights on and let it heat throughout the day...then let it cool over night. The heat wicked the break-free down around the pistons and rings. I was eventually able to get it to turn over without damaging the pistons... DAVE

 

I really dont want to ruin the piston.[/QUOTE]

Well, if it's that stuck, I'd say that the piston and bore are shot!

 

Give this stuff a try. He only wants $19.95 and a money back guarantee if it won't do the trick. www.enginerelease.com

 

PSI = Pounds per Square Inch

PSI is Pressure.
Pressure is Force Per Unit Area.

Force is not the same as Pressure.

The Force applied by a given Pressure changes according to how large an area the pressure is applied over.

1,000 PSI applied to 1 square inch of surface area yields 1,000 LBS of Force (1/2 ton).

1,000 PSI applied to 100 square inches of surface area yields 100,000 LBS of Force (50 tons).

Same pressure, two orders of magnitude difference in final applied force.

This is how hydraulic jacks work. Your arm exerts ~50 LBS of force on a piston with an area of ~0.5 Sq Inches, and a stroke of 1 inch. This action displaces 1/2 cubic inch of fluid, at a pressure of 100 PSI. The tiny piston is connected via plumbing to a much larger piston. This piston will have an area ~12 sq inches, so the force it exerts will be 1,200 LBS, and it will be displaced 0.042" per stroke of the smaller piston.

Get it?

This is the principle of hydraulic multiplication, and is the foundation of a great many of the most useful inventions in history.

Modern automotive brakes, construction equipment, forming and stamping presses, beer tappers, etc.