G43 Frozen Gas Cylinder - Comments Needed

NO, it doesn't harm the blue at all. It has the consistancy like water so it get into areas that normal oil products can't. But, it takes awhile. My friend and I had to remove the front sight on a few M1 carbines that had been on their so tight that I was afraid I would break the tool made just for this M1 application. I put a few drops on the sight and a couple of days later the sights were very easy to remove. I think it's the simplest solution to your problem and you would be sure that the dimple is the cause. One other thought maybe you could unscrew the the whole piston & cyclinder as one unit then just soak it. I had the problem I couldn't unscrew the piston without doing damage so i just used the Cabot's. But, I wouln't use high heat because you could alter the strength of the metal and cause more harm down the road.

I would love to soak the whole unit if I could get a grip on the cylinder. I'm going to try again this weekend and will keep this thread updated. I'll also keep an eye out for the product you mentioned.
 
I meant that the dimple or cylinder itself didn't move (as opposed to the sylinder moving and being prevented from coming off the piston by the dimple)

I used a wooded swedish or danish made carpenters clamp. This is one of those thingamabobs made of two wedges of wood with two coarse thread threaded shafts connecting them. The two wedges can be applied at a tapered angle to hold the gas block in place tot he barrel while applying torque to the piston.
 
After 3 months of trying to get the gas cylinder off, it finally decided tonight was the night to unveil the gas piston.

I want to publicly thank reich1900 for helping me out with this ordeal, as he allowed me to send him a small glass eyedropper to fill with Cabot's that he recommend I try. After placing a couple drops per day and waiting for about a week or so, it finally came off. The only mistake I made was not using enough masking tape and protection for the gas block when I was supporting it with a wrench while turning the gas piston off. I managed to scrap the block a bit, a bit disappointing as I almost had a perfect operation without making any scratches or damages. But, I'm glad it is finally off.

I've attached some pictures of how dirty inside the gas cylinder was. Thank you so much Bernie.

Shooter kit here I come..
 

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Stuck Cylinder

I am glad to see you got your cylinder off. Have you tried the piston yet? I had a ac44 with about the same setup as you stainless piston and early cylinder. I had changed the piston on a duv44 without any problems and thought that one should unscrew easy. Boy was I wrong. After soaking it for months I ended up taking to a friends shop and after a lot of heat two wrenchs and a big hammer we got it out. Now it works great with a shooters kit ejects almost every empty about 8 feet.
 
I am glad to see you got your cylinder off. Have you tried the piston yet? I had a ac44 with about the same setup as you stainless piston and early cylinder. I had changed the piston on a duv44 without any problems and thought that one should unscrew easy. Boy was I wrong. After soaking it for months I ended up taking to a friends shop and after a lot of heat two wrenchs and a big hammer we got it out. Now it works great with a shooters kit ejects almost every empty about 8 feet.

Yes, the piston was a bit stiff at first, but I got it off. I can only imagine that the last time it was off was when the factory just placed it in the gas block.

This Cabot's stuff really works, too bad it isn't made anymore.. It breaks the rust up with ease. The Kroil/heating method did not work with me, I may not have been applying enough heat, but I tried several times. I would recommend this stuff for stuck gas cylinders or pistons on G43s.
 
Frozen Gas Cylinder/Frozen Piston in block.

Hello there,

I'm also in the process of restoring my grandfather's G-43, and had/have the same issue; the gas cylinder cap was frozen onto the piston. I must say I like the original poster's rig for soaking the entire piston in penetrating oil, and I think that anyone with a similar problem will quickly discover that it's almost impossible to find Kano Kroil (penetrating oil) sold anywhere other than Amazon or their website, so in my case, I've been using Liquid Wrench. I've also heard people sing praises for PB Blaster, so, if you're impatient like me, you aught to be able to find either the LW or PB at most Lowes or Home Depots.

In regards to the makeup of the gas cylinder, the divot (as stated above), is supposed to be there; it's how the earlier models gas cylinder cap was manufactured, in two pieces. I had the same confusion when I watched a few g-43 breakdown videos via u-tube and saw a different design for the gas cylinder cap that was all one piece. This makes sense since at the time the German's were no doubt trying to find a simpler means to fabricate later model rifles using less material and fewer parts.

Regardless, I followed this advice in order to remove the gas cylinder cap: I plugged the barrel with cork (cleaning clothes will also do the trick) just past the gas block, then sprayed LW down the barrel and stood the rifle muzzle up and angled in such a way that the oil would flow through the gas port on the barrel through the gas block and into the piston and (hopefully) gas cylinder cap. I also doused the point where the piston cap was mating to the piston with oil as well, then used a very, very difficult technique: Patients.

After about a day or so of soaking, I discovered the same divot (which lead to my investigation), and also discovered that there was an ever so slight gap between the parts. What could I use to work penetrating oil into that gap?

Two things: The first was recommended; heating the tube with a propane torch, then dousing it in oil where the parts were mated (do not do this in an enclosed space without proper ventilation fyi), and then the second, which seems a bit unorthodox, but it worked:

Dental floss.

I found that I could douse the gap in oil, then slowly "saw" my way through the rust and cosmoline using the floss. Once I had enough of a gap exposed, I was able to stand the rifle on it's butt end, and using a piece of brass stock (because again, good luck finding brass punches sold anywhere other than online), and, with the piece of stock angle, I lightly began tapping downward on the gas cylinder and it moved! I kept at it and finally freed the two parts from one another!

What it exposed was a gas piston that is still in good shape, though slightly pitted with corrosion.

Now, here's where I could use some advice:

With the gas cylinder cap off, I quickly discovered that the piston is frozen into the gas block, and I'll be damned if I can get them free. For the moment, I've been applying heat to the gas block, then dousing it in LW in the hopes that the oil will eventually penetrate deeply enough to be able to separate the parts using a crescent wrench, but it's been several days of trying this process and I've made no forward progress. Does anyone have any suggestions?

Once freed, I'm planning on replacing the original piston with one of Rob Apfeltor's shooters kits. Thanks for any help you can provide.
 
Hello there,

I'm also in the process of restoring my grandfather's G-43, and had/have the same issue; the gas cylinder cap was frozen onto the piston. I must say I like the original poster's rig for soaking the entire piston in penetrating oil, and I think that anyone with a similar problem will quickly discover that it's almost impossible to find Kano Kroil (penetrating oil) sold anywhere other than Amazon or their website, so in my case, I've been using Liquid Wrench. I've also heard people sing praises for PB Blaster, so, if you're impatient like me, you aught to be able to find either the LW or PB at most Lowes or Home Depots.

In regards to the makeup of the gas cylinder, the divot (as stated above), is supposed to be there; it's how the earlier models gas cylinder cap was manufactured, in two pieces. I had the same confusion when I watched a few g-43 breakdown videos via u-tube and saw a different design for the gas cylinder cap that was all one piece. This makes sense since at the time the German's were no doubt trying to find a simpler means to fabricate later model rifles using less material and fewer parts.

Regardless, I followed this advice in order to remove the gas cylinder cap: I plugged the barrel with cork (cleaning clothes will also do the trick) just past the gas block, then sprayed LW down the barrel and stood the rifle muzzle up and angled in such a way that the oil would flow through the gas port on the barrel through the gas block and into the piston and (hopefully) gas cylinder cap. I also doused the point where the piston cap was mating to the piston with oil as well, then used a very, very difficult technique: Patients.

After about a day or so of soaking, I discovered the same divot (which lead to my investigation), and also discovered that there was an ever so slight gap between the parts. What could I use to work penetrating oil into that gap?

Two things: The first was recommended; heating the tube with a propane torch, then dousing it in oil where the parts were mated (do not do this in an enclosed space without proper ventilation fyi), and then the second, which seems a bit unorthodox, but it worked:

Dental floss.

I found that I could douse the gap in oil, then slowly "saw" my way through the rust and cosmoline using the floss. Once I had enough of a gap exposed, I was able to stand the rifle on it's butt end, and using a piece of brass stock (because again, good luck finding brass punches sold anywhere other than online), and, with the piece of stock angle, I lightly began tapping downward on the gas cylinder and it moved! I kept at it and finally freed the two parts from one another!

What it exposed was a gas piston that is still in good shape, though slightly pitted with corrosion.

Now, here's where I could use some advice:

With the gas cylinder cap off, I quickly discovered that the piston is frozen into the gas block, and I'll be damned if I can get them free. For the moment, I've been applying heat to the gas block, then dousing it in LW in the hopes that the oil will eventually penetrate deeply enough to be able to separate the parts using a crescent wrench, but it's been several days of trying this process and I've made no forward progress. Does anyone have any suggestions?

Once freed, I'm planning on replacing the original piston with one of Rob Apfeltor's shooters kits. Thanks for any help you can provide.


Hello, I think you have one thing right: patience. It took me 3 months to get the gas cylinder and gas piston off of my rifle. The Kroil technique did not work for me; neither did heating the gas tube. I know some folks will recommend heating the gas block and tube to remove it (almost everyone did to me), but that didn't seem like a very good idea since heating it excessively might cause some sort of damage to the pieces.

As I stated in some of my previous posts, I used Cabot's penetrating oil sent to me in a small eye dropper from a forum member here. I put a little bit on each day (did not soak, maybe a drop or two) and let it do the work. If you put it where the piston screws into the gas block, it will soak in around the threads - same thing happened with the cylinder. I think someone recommended to me using two wrenches, one on the gas block and one on the piston and turning is opposite directions to break it loose after it has been soaking for a while (week or two, applying a little bit everyday). Just make sure you protect the gas block or you will end up scuffing it.

I know it's hard to find, but that Cabot's stuff works like a charm - breaks down the rust and gunk. Too bad they don't make it anymore..

The most important thing is patience - it will come off, and will be worth the effort if you take your time and don't make mistakes. Keep us updated.
 
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Hello, I think you have one thing right: patience. It took me 3 months to get the gas cylinder and gas piston off of my rifle. The Kroil technique did not work for me; neither did heating the gas tube. I know some folks will recommend heating the gas block and tube to remove it (almost everyone did to me), but that didn't seem like a very good idea since heating it excessively might cause some sort of damage to the pieces.

As I stated in some of my previous posts, I used Cabot's penetrating oil sent to me in a small eye dropper from a forum member here. I put a little bit on each day (did not soak, maybe a drop or two) and let it do the work. If you put it where the piston screws into the gas block, it will soak in around the threads - same thing happened with the cylinder. I think someone recommended to me using two wrenches, one on the gas block and one on the piston and turning is opposite directions to break it loose after it has been soaking for a while (week or two, applying a little bit everyday). Just make sure you protect the gas block or you will end up scuffing it.

I know it's hard to find, but that Cabot's stuff works like a charm - breaks down the rust and gunk. Too bad they don't make it anymore..

The most important thing is patience - it will come off, and will be worth the effort if you take your time and don't make mistakes. Keep us updated.

Thank you for the response and your advice. I've had many sing the praises for Kroil, so I finally broke down and ordered some online, and am hoping it may do the trick. If not, then I'll have to see if I can find some of the Cabot's as you suggest. I'd also seen a video discussing the installation of one of Rob Apfeltor's shooters kits, and in the video the person wrapped the gas block in painters tape to prevent marring the surface, then used two crescent wrenches to remove the piston; one griping the block, the other the piston. I'll be sure to post a few pictures if I succeed.
 
Thank you for the response and your advice. I've had many sing the praises for Kroil, so I finally broke down and ordered some online, and am hoping it may do the trick. If not, then I'll have to see if I can find some of the Cabot's as you suggest. I'd also seen a video discussing the installation of one of Rob Apfeltor's shooters kits, and in the video the person wrapped the gas block in painters tape to prevent marring the surface, then used two crescent wrenches to remove the piston; one griping the block, the other the piston. I'll be sure to post a few pictures if I succeed.

That's what I did to remove the piston. Take your time, let the kroil soak in around the piston threads and gas block, a few drops every day. After that, walk away and forget about it until the next day. My piston was partially corroded like yours as well.

It will come off. Keep us updated.
 
Well... that sucked.

Success at last!

Here is a photo of the freed piston. That thing was on tighter than Mother Teresa's naughty bits.

Ultimately it came down to a combination of heat and KROIL: I heated the gas block and then sprayed the kroil into the gap between piston and the block and let it soak for about two days, occasionally repeating the process once or twice a day.

Finally, using a blow torch, I heated the gas block, and using two wrenches, was finally able to break the piston free of the block. I don't envy anyone who's G-43 has this problem, but it can be remedied. Thanks to everyone for their advice.

The next step is to replace the original piston with a shooters kit.
 

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original vs shooter kit comparison

Here's a comparison photo of the original gas piston and and gas piston cap vs the shooters kit which I just obtained from Apfeltor Waffenfabrik. The original has been cleaned and polished using a combination of soaking it in Kroil, then using emery cloth to polish it so it slides smoothly through the cap. There was also quite a bit of corrosion on the interior of both the piston and the cap, which was cleaned out using pipe-cleaners, a bronze bristle rifle bore cleaner, and q-tips to get the gunk out. Unfortunately, the passing of time left the original piston severely pitted and the end that faces outward from the gas block is chipped and pitted as well. I also thoroughly scrubbed out the gas block and used canned air to make sure that there was no blockage in the gas port hole bored into the barrel.
 

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