MEP-803a seized engine

[Rej1974]

So what's the trick for getting seized pistons out. I have my crankcase cover off and was able to get the center 2 pistons out and they are in great shape. The other two I cannot get them out. The piston closest to the generator took the brunt of the water damage. I have it unbolted from the crank but can't seem to get it to move. I soaked it with every kind of penetrating oil, ATF, etc. Seems to be stuck pretty good and is in a bad spot to really get any pressure on it. Just curious if there is a trick or if it is just a brute force process.

 

[AfghanVeteran2010]

I remember someone using Evapo-Rust on their set, might be worth a try.

 

[jamawieb]

So what's the trick for getting seized pistons out. I have my crankcase cover off and was able to get the center 2 pistons out and they are in great shape. The other two I cannot get them out. The piston closest to the generator took the brunt of the water damage. I have it unbolted from the crank but can't seem to get it to move. I soaked it with every kind of penetrating oil, ATF, etc. Seems to be stuck pretty good and is in a bad spot to really get any pressure on it. Just curious if there is a trick or if it is just a brute force process.

I've had good success with heating the top (around the sides) of the piston with a torch and then dumping ice into the cylinder, then right after you dump the ice, smack the piston with a mallet. The hot and cold cause contracting and expanding, then the sudden smack with a mallet breaks it loose. Most of the time I use a piece of wood on the piston and hit it with a steel mallet.

 

[Kenny0]

So what's the trick for getting seized pistons out. I have my crankcase cover off and was able to get the center 2 pistons out and they are in great shape. The other two I cannot get them out. The piston closest to the generator took the brunt of the water damage. I have it unbolted from the crank but can't seem to get it to move. I soaked it with every kind of penetrating oil, ATF, etc. Seems to be stuck pretty good and is in a bad spot to really get any pressure on it. Just curious if there is a trick or if it is just a brute force process.

If your connecting rods have been removed, connect them back up. Use a good penetrant, are some good ones out there, evaporust, 50/50 mix of ATF and diesel fuel, and I like essentialube. Not very common, but I think it works very well. no matter what you use, give it time to work (days). Then remove the starter and use a prybar on the teeth of the ring gear of the flywheel. Work back and forth even if you don't feel it move. Don't get too carried away with brute force because this applies a lot of torque. If after a few times you don't fell it move, wait a couple of days and try again. Once you get it loose enough to move, then use a hone and clean as much of the rust out as possible and keep working back and forth until you can get to move a complete revolution, then remove and do your repair work.