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Weird piston seal

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Camel73:
Well, I cleaned up the piston cylinder but I thought it was strange that scuff marks were near the seal too so I looked down the length of the tube towards the seal and... no seal. Off center, I believe, check the pics.

Is that what a breech seal looks like after 500 shots? I should have ordered one of those too I suppose. Yesterday I put the order in for 2 small apex and some moly paste..

The button trick looks like the way to go, I'll have to research it some more... tolerances are pretty tight in there.

Am I wasting my time waiting for seals when I should be getting a new piston cylinder? or writing the company? Lol... eye roll

ricksplace:
Check it again after you have installed the new seal. The OEM seal may have been distorted from a bad installation. A burr on the reverse taper could push the seal to one side too. If the reverse taper is that far off center, the piston should probably be replaced. Crosman OEM parts are cheap and available.
You can temporarily soften the new seal prior to installation by immersing it in hot water.

The old seal is sometimes difficult to remove. If you can manage it without shoving a small screwdriver through the fleshy part of your hand, you're doing better than many of us here.

Your breech seal appears to be undamaged, but installed higher on one side. I'd remove it, clean up all the burrs and reinstall with a few wraps of dental floss underneath. Lay a piece of tissue paper over the breech, then fire the gun with the pellet you normally use. If the tissue paper stays put, you're good (no leaks). If the tissue paper flies off, you have a leaky breech seal.

Camel73:
Those new seals look pretty good, and tough. The old one came off pretty easy.. I remember it being a little loose, but not the new one! Ha, super tight and no glaring concentricity issues like I thought, although I never did actually measure it.. I threw in another pic of the old seal to show what the inside looked like  :o

After taking the od down while test fitting, I got it down to about 12 lbs pressure on the old fish scale and it seemed consistent through the tube. After firing it a bit I took it apart to inspect - the piston cylinder was noticeably easier to move. CPHP 14.3's average was 625 fps.  Hmm... 

Groups were still huge but not grotesque, ha. 3-4" at 20 yards. So I went down back and got me some fender washers... thinned them out too much, lol. Ok, you little... next was brass self locking nuts. De-nutted the little suckers with a hacksaw and voila! Brass washers. If you're wondering why I went through this instead of buying them, I did... any brass (or regular) washers weren't thick enough. At this point I did get some worthy results.

Target guide:
- RWS superdome pellets
- Center (about 8 yards) screwin around, gettin above center
- Top left (20 yards) 6 shots, not taking too much time
- Bottom left (20 yards) Took 6 more shots, made an adjustment to center, took my time, and bammo! bout a half inch 3 shot group
- Bottom right (40 yards) I didn't touch the scope and I can't remember where I was aiming, the target above or the end of the bigger right leaf, but just got lucky actually being close. Just wanted to get a group size. I was going to take 10 shots but 7 and 8 missed altogether
- Top right (20 yards) 2 shots - screws began to loosen up. No locktite yet, still r&d.

This was with a Simmons 3x9x40SP off my marlin model 60SS.

When I first put the brass washers in, the barrel was a bit stiff but after the RWS superdomes I tried CP hollow's and magnums, Benjamin variety pack (all of these roughly 14 grains) and Crosman powershot penetrators at 16.7 grains.

While testing these, the barrel got to swinging free again, checked the pivot bolt and still tight. At this point I wanted to put some muscle on it but thought against it.

Groups have opened up a bit again and I keep finding the pellets wanting to go right... I believe locktite will solve the wanting to go right.

The machine work is pretty rough on this thing so I'm thinking the brass washers have sunk into the machining grooves just enough... or somethin... lol. Looking at some pics of the crown, maybe I should do that too.

I haven't had time to take the thing apart again yet to see what is happening, although I probably could have in the time it took me to write this, lol, but I thought I'd give an update :)

Camel73:
Oh ya, I did the tissue test and it passed.
Was just reading on how the shoulder on the pivot bolt could be too long also... jeepers.

Thanks again to all who reply, your input is helping me keep my sanity.. what's left of it :)

OleTomCat:
Couple of things you need to do:

1.) LocTite, BLUE ONLY, will help, make sure you clean the threads on the screws and tapped holes before applying and let it sit 24 hours.
2.) That scope will not handle the recoil and will cause you problems, Get one of these:
3.) Read this thread: http://www.gatewaytoairguns.org/GTA/index.php?topic=51555.0, it goes over all of the beginner stuff that everyone needs to know about a springer from cleaning and setup to hold and shooting practices..
4.) Your initial seal probably failed due to over lubrication causing detonation, put some Moly behind the seal but not in front of it, if you pull it apart and your have soot there you are dieseling.  You may need to clean out the old lube again.
5.) Pivot washers, get some M8 brass washers from your local hardware store, they should be easier to find up there than down here. use a little bit of Moly on both sides of the washers when you install them.
6.) when you tighten the pivot bolt hold the action vertical and the barrel horizontal, the barrel should drift down slowly of it's own weight, if it falls you have it to loose, if it just stays there you have it to tight.

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