O Ring

NorthMaine

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How much slop are we talking here to believe the o ring is bad? Both my pumps rock a little bit in my hand which is evident watching the pump arms as I’ll call them move in unison. Maybe a 1/16th of an inch of movement. Both are the same.
That sounds like they are bad. Not having any exoerience when I bought mine, I thought it was normal but once you replace it and see what it feels like after it’s night and day difference.
 
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Well decided to work on two rifles that I have never replaced the "O" ring on and also needed to be broke down for a good cleaning. First one was a 7600 and tried taking the tube off and would not move. Put a little heat to her after seeing the thread "Mainewoods" had and she came off fairly easy which I was surprised. Picked up two packs of the Danco #40 rings when I was at Lowes yesterday and figured I would replace it since it was making a little bit of noise, but wasn't too bad. The new "O" ring fit tighter and was a little tougher in putting back together but took care of what little noise there was. Be interesting to see how this ring lasts compared to the other one.

Rifle #2 (760) however I was not so lucky. Put a good amount of heat on the tube of that sucker and could not get her to free up. Let everything cool down and put some penetrating oil inside the tube and at the base and going to let her have a good soaking for a few days to see if that helps to loosen things up, hopefully that works. Anyone else have one like that and not come off after applying some heat etc ?

IMG_3581.jpg
 
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Mainewoods

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Glad the heat worked in the first rifle, and hopefully it’s good to go for a long time. Once you do it once, it seems kind of easy and should be, since we are only replacing a .50 cent oring.

How lose is the 760, pretty noticeable? Once I hit mine with the heat and a little snap of the wrist, it came lose.
 

NorthMaine

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Nice work!

May need more heat than the butane. The hardest part for me was removing the rail assembly off the barrel. It just didn't feel right twisting it off, it wanted to catch and damage the barrel. I ended up just prying each side individually and sliding it straight up and off the barrel.
 
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Finally got the one off of the 760 carbine today, which was my fathers. Glad I did because that one needed some attention and cleaning. Especially on the inside corners of the rail where the firing mech sits. You wouldn't believe the amount of crap that came out of the receiver and inside the tube when I sprayed it down. Also had a lot of red locktite on it which I had to increase the heat setting on the torch I had. Snapped one roll punch but after I did that I was still able to use the short end which seemed to work better. Couple light taps with a hammer and she broke free. Seems to me for the rifles I have that the Danco #40 "O" ring seems to fit better on the regular 760's then the two 7600 I have. Work on a few other ones next week, might just use the penetrating oil now on the other ones I want to do inside the tube which seemed to help some.

IMG_3583.jpg
 
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JDK

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I finally grew a pair and took mine apart. Not bad at all and no red loctite. The O ring was in 2 pieces in the action. I guess my only concern was the first 2-3 inches of the tube was heavily rusted and I can't see a way to prevent that. It cleaned up nicely and is far more solid. I ended up getting the O ring from a local hardware store as my Lowes did not have them.

Thanks to everyone for the tutorials.
 
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I finally grew a pair and took mine apart. Not bad at all and no red loctite. The O ring was in 2 pieces in the action. I guess my only concern was the first 2-3 inches of the tube was heavily rusted and I can't see a way to prevent that. It cleaned up nicely and is far more solid. I ended up getting the O ring from a local hardware store as my Lowes did not have them.

Thanks to everyone for the tutorials.
Is yours a 7600 or 760 ? Out of all the ones I've done so far it seems the 760's most often are the ones with the red loctite
 

NorthMaine

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I finally grew a pair and took mine apart. Not bad at all and no red loctite. The O ring was in 2 pieces in the action. I guess my only concern was the first 2-3 inches of the tube was heavily rusted and I can't see a way to prevent that. It cleaned up nicely and is far more solid. I ended up getting the O ring from a local hardware store as my Lowes did not have them.

Thanks to everyone for the tutorials.
Maybe a couple coats of car wax to repel the water?
 

nsheeh

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Hey guys first off i wanted to say thanks for the tutorials on the o ring replacement wouldnt have done it if i did have them. So i did the oring on a 7600 06 . A 3/16” punch had no problem getting the tube unscrewed. getting the barrel of the bars was alittle difficult ( not wanting to scratch anything) but the fore end tube had a little bit of rust making the new o ring fit very tight and difficult to slide( nearly impossible to cycle) . So i pulled it all out again reamed it with wire brushes and gun blaster then a few clean patches then an oil patch and another clean patch put it all back together. Cycling is “ok” now still pretty stiff. The stiffness is to be expected but i dont know if i should go back in and polish both tubes as im sure it will help the cycling of the gun. Either way im glad i did it, it is much quieter now and was not as overwhelming as i made it out to be. Also helped me to get in there and give it a real good cleaning which it needed. So thanks again this thread was very helpful.
 

NorthMaine

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Hey guys first off i wanted to say thanks for the tutorials on the o ring replacement wouldnt have done it if i did have them. So i did the oring on a 7600 06 . A 3/16” punch had no problem getting the tube unscrewed. getting the barrel of the bars was alittle difficult ( not wanting to scratch anything) but the fore end tube had a little bit of rust making the new o ring fit very tight and difficult to slide( nearly impossible to cycle) . So i pulled it all out again reamed it with wire brushes and gun blaster then a few clean patches then an oil patch and another clean patch put it all back together. Cycling is “ok” now still pretty stiff. The stiffness is to be expected but i dont know if i should go back in and polish both tubes as im sure it will help the cycling of the gun. Either way im glad i did it, it is much quieter now and was not as overwhelming as i made it out to be. Also helped me to get in there and give it a real good cleaning which it needed. So thanks again this thread was very helpful.
I think it will break in with time. You're just so used to no o-ring haha.
 
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