Removing stuck pistons
 

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

Re: Removing stuck pistons
 

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.

Re: Removing stuck pistons
 

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

Re: Removing stuck pistons
 

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?

Re: Removing stuck pistons
 

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

Re: Removing stuck pistons
 

Thanks, have you tried this? Bob

Re: Removing stuck pistons
 

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.

Re: Removing stuck pistons
 

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.

Re: Removing stuck pistons
 

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.


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

Re: Removing stuck pistons
 

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?