View Full Version : Stuck 74 brakes.
I’ve got two 74s - an SAR-2 with a Romanian 22mm FSB and brake, and an SLR-104 and the brakes seem to be stuck in place, presumably carbon-locked. They have had some modest quantities of late 1970s 7n6 through them as well which probably didn’t help matters.
I can’t get these things off. I’ve tried a couple different types of “penetrating oil” - Free All and PB Blaster - soaked them from both sides - from the rear of the brake, and at the front, on the inside of the “expansion chamber” or whatever the main body of the brake is called - basically trying to get the oil into the threads from both sides. I’ve stuck various items through openings at the end of the brakes in an attempt to get enough leverage to twist them off, and still no luck.
Anyone have a proven method for removing these things?
Only things I can think of would be to try a torch to heat it while twisting and failing that an ultra sonic cleaner deep enough to fit the brake in.
Ned Christiansen
03-06-22, 10:40
Try pushing in on that little spring-loaded thingy.
Just kidding.
Those threads are so sloppy-- makes them easy to pack full I guess. I've never had to get a stuck one off but if I did I'd start just as you have and graduate to the torch as suggested. The "sloppy" ought to work also in favor of breaking free.
Sometimes gorilla torque is not so much the way as a lot of cycles of lesser torque being applied, as with an air wrench. Of course your brake doesn't happen to have a 3/4 hex on the end do you'd have to make something.
Barring that I would also put some torque on it and give it some sharp raps on the outside of the threads, not with a rubber hammer but with something that delivers shock. A steel hammer and large punch but with a penny under the punch to keep from knarfing things up or some variant thereof I have a biggish piece of copper I use for such things). The wall thickness is not tremendously thick there so use caution.
Try pushing in on that little spring-loaded thingy.
Just kidding.
Those threads are so sloppy-- makes them easy to pack full I guess. I've never had to get a stuck one off but if I did I'd start just as you have and graduate to the torch as suggested. The "sloppy" ought to work also in favor of breaking free.
Sometimes gorilla torque is not so much the way as a lot of cycles of lesser torque being applied, as with an air wrench. Of course your brake doesn't happen to have a 3/4 hex on the end do you'd have to make something.
Barring that I would also put some torque on it and give it some sharp raps on the outside of the threads, not with a rubber hammer but with something that delivers shock. A steel hammer and large punch but with a penny under the punch to keep from knarfing things up or some variant thereof I have a biggish piece of copper I use for such things). The wall thickness is not tremendously thick there so use caution.
Heh, on the SAR-2 I actually drove the retaining pin in the FSB out and removed the plunger pin and spring via the rear of the FSB so that would at least be one less hassle to deal with. My SAR-2 is the one of the two guns I’ve kinda been rougher with so far in this process, since it’s already comically inaccurate compared to my SLR-104 anyway, I’m a bit less concerned about dicking it up
I don’t have a torch handy so I’ll give the hammer method a try for starters.
If I get these brakes off I think I’ll put some aeroshell grease on the threads and maybe try not be so negligent about cleaning.
Got ‘em. Basically ended up sticking the FSBs of each rifle, wrapped in cloth and foam, in a vise, making a breaker bar out of a three foot section of metal pipe and putting it over a thick steel punch stuck through the brakes. Required a shocking amount of force to get these things undone. I moved the front sight drum on my 104 in the process, thus losing my perfectly dialed in zero. Hopefully I didn’t do any other damage.
Surprisingly little rust under the brakes for how stuck they were…
Got ‘em. Basically ended up sticking the FSBs of each rifle, wrapped in cloth and foam, in a vise, making a breaker bar out of a three foot section of metal pipe and putting it over a thick steel punch stuck through the brakes. Required a shocking amount of force to get these things undone. I moved the front sight drum on my 104 in the process, thus losing my perfectly dialed in zero. Hopefully I didn’t do any other damage.
Surprisingly little rust under the brakes for how stuck they were…
Glad to see you got it done.
Glad to see you got it done.
Tried whacking on them with a hammer/punch to no avail, so I came to the realization there was no way forward besides brute force.
I’ve slathered the threads in aeroshell grease, so hopefully that helps mitigate this issue going forward
Tried whacking on them with a hammer/punch to no avail, so I came to the realization there was no way forward besides brute force.
I’ve slathered the threads in aeroshell grease, so hopefully that helps mitigate this issue going forward
I can't help but wonder if a high temp anti-seize wouldn't be better for this application than Aeroshell.
I can't help but wonder if a high temp anti-seize wouldn't be better for this application than Aeroshell.
Hmm, I just happened to have aeroshell on hand so that’s what I used. But now that you mention it I think I may check my local hardware store for the anti-seize
Hmm, I just happened to have aeroshell on hand so that’s what I used. But now that you mention it I think I may check my local hardware store for the anti-seizeThey'll have it. If it were me, I'd use the copper stuff if available.
Ned Christiansen
03-06-22, 20:41
My opinion, there is probably nothing you can use that will prevent the intrusion of crud at ~ 10K PSI "uncorking" pressure. I almost suggested epoxy, actually. Probably would resist for longer the intrusion of crud. I think the #1 solution is regularly taking it off for a clean and lube.
Got ‘em. Basically ended up sticking the FSBs of each rifle, wrapped in cloth and foam, in a vise, making a breaker bar out of a three foot section of metal pipe and putting it over a thick steel punch stuck through the brakes. Required a shocking amount of force to get these things undone. I moved the front sight drum on my 104 in the process, thus losing my perfectly dialed in zero. Hopefully I didn’t do any other damage.
Surprisingly little rust under the brakes for how stuck they were…
Ouch, at some point I'd have just left them on. Canted FSB AKs are one of the things that drive me up a wall.
Ouch, at some point I'd have just left them on. Canted FSB AKs are one of the things that drive me up a wall.
I was concerned about rust and corrosion but as it turned out that was less prevalent than anticipated. Basically I thought the problem was more serious than it ended up being but once that was apparent, what was done was done.
I did paint mark the FSB on the SLR-104 beforehand and as far as I can tell, despite moving the drum, the FSB’s position relative to the barrel did not change. So I doesn’t look like I imparted any cant to it. So as long as I didn’t bend the barrel itself or something stupid like that it should be okay, it just needs to have its windage re-dialed in.
The SAR-2 has always been a dumpster fire with regard to accuracy anyway so there’s not much I could do to that gun to make it shoot worse…
I was concerned about rust and corrosion but as it turned out that was less prevalent than anticipated. Basically I thought the problem was more serious than it ended up being but once that was apparent, what was done was done.
I did paint mark the FSB on the SLR-104 beforehand and as far as I can tell, despite moving the drum, the FSB’s position relative to the barrel did not change. So I doesn’t look like I imparted any cant to it. So as long as I didn’t bend the barrel itself or something stupid like that it should be okay, it just needs to have its windage re-dialed in.
The SAR-2 has always been a dumpster fire with regard to accuracy anyway so there’s not much I could do to that gun to make it shoot worse…Who knows, maybe you improved the accuracy? [emoji13]
Who knows, maybe you improved the accuracy? [emoji13]
I’d be lying if I said that thought hadn’t crossed my mind haha
I was concerned about rust and corrosion but as it turned out that was less prevalent than anticipated. Basically I thought the problem was more serious than it ended up being but once that was apparent, what was done was done.
I did paint mark the FSB on the SLR-104 beforehand and as far as I can tell, despite moving the drum, the FSB’s position relative to the barrel did not change. So I doesn’t look like I imparted any cant to it. So as long as I didn’t bend the barrel itself or something stupid like that it should be okay, it just needs to have its windage re-dialed in.
The SAR-2 has always been a dumpster fire with regard to accuracy anyway so there’s not much I could do to that gun to make it shoot worse…
My SAR-1 actually shoots pretty straight. Is it possible that the bore diameter is wrong on your 5.45? Is that a thing with AKs?
My SAR-1 actually shoots pretty straight. Is it possible that the bore diameter is wrong on your 5.45? Is that a thing with AKs?
There was an infamous batch of Century assembled Tantals that IIRC had 5.56 diameter barrels instead of 5.45 ones. So anything is possible. But where the SAR series guns were all Cugir made, except for the compliance parts added stateside, I think mine is just inaccurate. With irons it was doing like 8” groups at 100yds with 7n6 while my SLR will do like 3” with the same ammo.
The amount of crap caked around the muzzle of the SAR had me wondering if maybe the buildup was affecting the accuracy somehow, don’t ask me how exactly, something with the crown maybe, because while it was never really a tack driver it did seem like the gun actually got *less* accurate.
There was an infamous batch of Century assembled Tantals that IIRC had 5.56 diameter barrels instead of 5.45 ones. So anything is possible. But where the SAR series guns were all Cugir made, except for the compliance parts added stateside, I think mine is just inaccurate. With irons it was doing like 8” groups at 100yds with 7n6 while my SLR will do like 3” with the same ammo.
The amount of crap caked around the muzzle of the SAR had me wondering if maybe the buildup was affecting the accuracy somehow, don’t ask me how exactly, something with the crown maybe, because while it was never really a tack driver it did seem like the gun actually got *less* accurate.
Every SAR gun I've ever heard of had the original barrel. I'm assuming yours had a replacement FSB since you had threads for a brake.
My SAR 2 wasn't the most accurate AK I've ever owned but it was within the AK "margin of error" that one expects from AKs that have sight on straight.
Every SAR gun I've ever heard of had the original barrel. I'm assuming yours had a replacement FSB since you had threads for a brake.
My SAR 2 wasn't the most accurate AK I've ever owned but it was within the AK "margin of error" that one expects from AKs that have sight on straight.
Yeah, original barrel but replacement Romanian 22mm threaded FSB and brake.
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