Removing stuck pistons

[bobdylan]

Looking for proven techniques for removing pistons, one thing taht sounds good is, after soaking with? pack cylinder with grease, put a head that valves seal tight. modify spark plug and instal grease zerk, use pressure from grease gun to shve piston out. Has anyone tried this? Bob

[George Bongert]

Originally Posted by bobdylan

Looking for proven techniques for removing pistons, one thing taht sounds good is, after soaking with? pack cylinder with grease, put a head that valves seal tight. modify spark plug and instal grease zerk, use pressure from grease gun to shve piston out. Has anyone tried this? Bob

Greetings Bob!

I have heard of the grease gun method, although I've never tried it myself. As to soaking the cylinder(s), a friend of mine recommends a 50/50 mixture of laquer thinner and brake fluid to break the bond between the rusted cylinder and piston. Again, I never tried it myself, but he claims it works well. If you try it, let the rest of us know whether it works or not.

[ilvracn]

An old mechanic once told me, water is what stuck it, so it will work the best to unstick it. I found a product called evaporust. It is water based, and it eats rust like you would not believe. It may take a few days or weeks, but i think it will work.
Website orisonmarketing.com 800-460-2403

[FetchMeAPepsi]

I don't know anything, but can you just put a block of wood on them and use a BFH to pound them out?


Maybe putting a jack under them will push them out the top?

[abus319]

+1 for evaporust assuming its the rings that are stuck and your goal is to salvage the pistons.

[bobdylan]

Thanks, have you tried this? Bob

[ilvracn]

Haven't tried it on pistons. I have a pistol that my uncle found when plowing about 50 years ago. I think it dates back to the late 1800 era. Tried soaking it in diesel fuel for 2 years, did no good. I put the pistol in a bucket of evaporust and soaked it for a couple months. I was then able to rock the cylinder a little bit. I was pretty excited about that. So put it back in bucket, but did not get back to it for a couple months. Wheni pulled it out another chemical reaction occured, and a white powder had formed on it. Pistol stuck again. What a bummer. So dont leave evaporust in too long.

[bobdylan]

I think on a small part I would use electrolosis, using a bucket, battery charger some rebar. There some on youtube, I keep thinking I am going to try it, but there is the twenty unfinished projects.

[GMCDAC]

Originally Posted by bobdylan

Looking for proven techniques for removing pistons, one thing taht sounds good is, after soaking with? pack cylinder with grease, put a head that valves seal tight. modify spark plug and instal grease zerk, use pressure from grease gun to shve piston out. Has anyone tried this? Bob

The grease method sounds like a pretty good idea, it sure works slick for pressed in pilot bearings. The first pic below is a couple different rust breaker sprays I've had good luck with before. I've heard kerosene and ATF mix works well but never tried it.

Originally Posted by ilvracn

Haven't tried it on pistons. I have a pistol that my uncle found when plowing about 50 years ago. I think it dates back to the late 1800 era. Tried soaking it in diesel fuel for 2 years, did no good. I put the pistol in a bucket of evaporust and soaked it for a couple months. I was then able to rock the cylinder a little bit. I was pretty excited about that. So put it back in bucket, but did not get back to it for a couple months. Wheni pulled it out another chemical reaction occured, and a white powder had formed on it. Pistol stuck again. What a bummer. So dont leave evaporust in too long.

Cool find! I wish I could remember how Mom de-rusted this pistol about 45 years ago but it came out well. I remember she soaked it in something for quite a while in our utility room and I don't remember it having a bad smell or anything. She found it while digging for old bottles at a long-gone railroad station, and it is also from around the same era.

Sorry about the brief hi-jack!

DAC

[abus319]

I haven't tried the evaporust on a stuck piston yet. My thoughts were that eliminating the rust bond between the rings and the cylinder wall with a non damaging product like evaporust might be a better first step than applying force.
I know these pistons are stout but i would be concerned about breaking or deforming a ring land with the grease gun method.
On my 478 I used a mix of trans fluid and diesel in the cal, and built a torque plate to attach an impact to the end of the crank. Two or three second burst, reversing each time, several times a day broke it loose.
Do you have the heads off, or is this one of the engines that was stored without the heads? if so how do they look?