Other Late 50's/early 60's Slavia 618 piston and breech seals?

[rmueller23]

Good morning,

I have been handed down my grandfather's Slavia 618 air rifle. As best my father can recall it would have been purchased new in the late 1950s or early 1960s. It's in pretty good condition for the age, although the breech seal is missing a chunk and the piston seal may have needed replacement. I fear I may have made things more difficult by removing the piston seal, and it may have been preferable to try to clean and recondition it---regardless, that's where I am now. The old seal appeared to be leather, and was quite hard below the surface. It was cut off with a razor knife. The outer washer, let's call it, rotates on the stem, but does not move down--I presume it's seated on a shoulder machined into the stem. It appears to be held on by end of the stem being peened over. It is not held on by a screw, therefore cannot be readily removed/reinstalled.

I initially ordered this kit from Custom Airseals Australia, from memory I thought the piston looked similar--but thankfully upon further review caught their note about it being for plastic seal pistons only. They confirmed it would not work, and that I would instead need their 22MM leather seal adapter kit:

DIANA GECADO 22 23 LEATHER SEAL ADAPTOR MILBRO G22 G23 G75 G76 WINCHESTER 422 | eBay

Find many great new & used options and get the best deals for DIANA GECADO 22 23 LEATHER SEAL ADAPTOR MILBRO G22 G23 G75 G76 WINCHESTER 422 at the best online prices at eBay! Free shipping for many products!

www.ebay.com

They advised I would need to "...face off then drill and tap the piston 4mm metric to accept the adapter screw". I presume they mean cut the piston seal stem off flush with the main body of the piston. then drill and tap for the screw. Secure the black piece with the screw, then snap on the red poly seal.

The 618 has heirloom value for me personally, all things being equal I would rather not modify any parts unless absolutely necessary. Is anyone aware of other seals or methods that I am not finding for installing a new seal on this style piston assembly besides the solution from Custom Airseals Australia? If I have to I have to....

Thank you,

-Ryan

 

[marflow 777]

but is the center rod also the same rod that hold the seal and all of that was manufactured together
i did find a video of a early 318 that had a stem break and he made a seal out of hot glue but i question that would hold up very long
these might have been made with the idea it would never be rebuilt but then they changed it so they could be rebuilt
i did look for a replacement piston but did find much

 

[rmueller23]

but is the center rod also the same rod that hold the seal and all of that was manufactured together
i did find a video of a early 318 that had a stem break and he made a seal out of hot glue but i question that would hold up very long
these might have been made with the idea it would never be rebuilt but then they changed it so they could be rebuilt
i did look for a replacement piston but did find much

That's how it appears--center rod is one piece from piston end to the end that catches the sear. That's kind of what I was thinking, that these were not manufactured to be serviced initially, or they presumed you would just buy a new piston assembly if you wore a seal out.

The hot glue is an interesting solution in a pinch. That being said, keeping this usable and useful for chipmunk abatement and firearms introduction for our boys when they get old enough is also important---so I'm leaning towards making the mods and installing the more durable seal from the Australian company. Thanks

 

[marflow 777]

so i said i looked for a newer 618 piston and came up empty
now the video shows the piston stem broken off and the center of the stem looked very poor material wise
and if the post was pressed on front to back which would make sense, if you cut the front off then how is held together
so if you kept the post in front and epoxied the adapter on for a modern seal would that work
i concern is cutting the front stem off flush and drilling and tapping and it's ability to stay in the piston
the breech seal can be found or even made out leather but the piston seal is the problem
the normal size for the screw in those adapters is in the 4-5mm size range
maybe cut the front stem down on a lathe but keep some of the full-size part intact, i don't know

the problem i have is i don't know how the complete piston was made, how all the part interact with each other but welding them together could also be a way to do it

only if it was easy

looking a little more, is the piston rod screwed into the front of the piston
in the video at 3:22 he shows the broken off stem and the fracture is only in the center, now if you look at this picture enlarged there seems to be a gap at the front of the rod
just guessing at this point
could the piston seal been split to slid on the head when new, the cylinder would have held it together