nitro trail NP seal

[ericf]

I just took usps delivery of a new piston (main?) seal for the Ben trail NP.
I'm a little concerned since it appears to be a plastic molding. Nylon, HDPE, delrin, plastic, what is it?
Is there any special fitting considerations to be aware of ?
There appears to be very little, if any,  flex to the material.
Does it "snap" onto the piston?
Thanks

[Motorhead]

Yes a Synthetic ... yes there stiff ... yes they snap on.

Main tube should be Lightly honed to a cross hatch pattern, Deburred around ALL holes & slots on receiver seal will pass over when assembling !!!!!!!!

[robert w]

if its real hard to try to put on I let it set in HOT water for a while ,it helps to install on the piston

[jimdandy]

the seal can pop on it helps to turn as you push down and then cut a pop can and make a sleeve around your piston and seal and use that to help you get the piston back in without damage to the seal 

[OleTomCat]

Eric,

Did you  get your seal from Crosman or ARH, the ARH is a little more pliable than the Crosman and is easier to size, the Crosman seal is pretty hard..

[ericf]

I ordered all items from Crosman, washers, spacers and seals

[jimdandy]

yes you need to get the piston seal from ARH its sized right where the crosman seal is under sized this is the seal you need I have this seal also
http://www.airrifleheadquarters.com/catalog/item/251485/6616786.htm and get these washers http://www.airguntoys.com/ and I have these washers and dont try and save a buck and make your own just get the cnc machined ones. Be careful not to mess the pivot screw up real pain in the butt!!

[OleTomCat]

yes you need to get the piston seal from ARH its sized right where the crosman seal is under sized this is the seal you need I have this seal also
http://www.airrifleheadquarters.com/catalog/item/251485/6616786.htm and get these washers http://www.airguntoys.com/ and I have these washers and dont try and save a buck and make your own just get the cnc machined ones. Be careful not to mess the pivot screw up real pain in the butt!!

Jim,

I believe that is the wrong seal for a Trail, the trail uses a seal that is .999~1.030", try the Tesla or apex seals, they are closer to the correct size and require little to no sizing...

This kit has both: http://www.airrifleheadquarters.com/catalog/item/251485/5499150.htm

[ericf]

Jim, just curious why a manufacturers OEM part would be "under sized"? I haven't disassembled for the install yet. But I have taken it apart and cleaned every thing up . Noticed a lot of flashing around the edges of the piston seal which I carefully removed (it was folded back causing a mis-shapened seal). ANyway, I thought I'd have one available for "next time".
How much oversized should it be as compared to the bore?
 If it is "undersized" could a heat gun soften the material so it could be expanded ?  Sounds like a "cheap" out , but just thinking out loud.

[jimdandy]

for my trail np 1500 xl and the research I did lead me to that seal its a .001 bigger than the oem not much huh
http://www.airrifleheadquarters.com/catalog/item/251485/6616786.htm this is the seal that I ordered and as you can read on this page its over sized
from what the oem is maybe there different where its not an xl anyway I would get after market thats just me

[JR]

I have replaced the seals in both of my Trails, normal Trail and XL 1100 just the last month. If your trail is just a normal trail NP then a couple of these links are wrong for your gun, The link Oletomcat posted is the seal you need Gamo/B18-B19. The other links to the Walther Talon Turk seal is for the Trail XL and wont come close to fitting the normal Trail NP. Look at the size differences on the seals and you can see the one is quite a bit bigger.

I used OEM Crosman seals on both my NP and XL, but I plan on upgrading to ARH seals next, lot better quality seal.  The original seal in my normal Trail fit ok, little loose and was hard, but had metal embedded in the end and had feathered edges. The new seal fit good and gained me a few FPS and closed up my ES to 8 FPS. The original seal in the XL was under sized and didn't even touch the walls of the chamber. All I had to do to get the piston out was tip the gun back and the piston slid right out. The new seal for the XL was around ,036 larger and took some time to get back in the gun.

Both of the new seals had more drag than the original seals, which will wear in as you shoot it. If the seal is way over sized and drags to much that isn't a good thing either but unless it's way bad should still wear in but take longer. None of these guns have a compression tube that is perfect in diameter, a softer seal has a little more flex to make up for that.