Dissassembling an old Trail NP XL1100

[unionrdr]

I'm having trouble getting the center of the safety arm assembly to come out of the bottom of the action so I can pull the piston out? Could use a little help here!

* Got a little help from Wayne52. It turns out, you have to remove the barrel bolt in order to turn the barrel/safety linkage assembly 90degrees to the action tube. This allows the flange on the safety linkage to be removed from behind the piston head. So now that it's apart, I'll continue on making the video of the rebuild I'll post here for future reference.

[RobertMcC]

Unscrew and remove the barrel bolt. To get it out easier.



When you put the trigger group back in, do this..

[Roadworthy]

I think I'd call it the cocking arm but I've always disconnected the anti beartrap linkage from it, thereby liberating the trigger assembly.

From there you should only need to pull the cocking arm out of the cocking slot after locating the foot at the wide point in the slot.  You may need to work it around a bit to achieve the correct angle but removal is usually straightforward.

[unionrdr]

Got it. I had to remove the barrel bolt, turn the barrel linkage 90 degrees to the action tube to get the flange to come out. Rick Uestler's video with the NP2 is a little different than these older ones.

[Roadworthy]

Helpful (to me) hint - I do not remove the barrel unless absolutely necessary.  I disconnect the anti beartrap linkage from the trigger group.

After removing the gas strut I break the barrel allowing it to pivot down.  The knee action of the cocking linkage allows the angle to change enough to remove the linkage from its slot.  I can then easily remove the piston.

[unionrdr]

I couldn't get that to work on this one for some reason? Idk, maybe I didn't do it quite right? Gotta start cleanup and reassembly today. Gotta figure out where a rectangular metal stamping goes that fell out?

[unionrdr]

And another dumb problem. Look at the taper on the seal land, then the taper on the inside of the seal. How the heck do I get it on, groove up, if it looks like it'll only go on groove down? Is there some kind of seal expander for these hard seals or a trick? Everything else seems easy enough...just these couple little things.

Here's a better look at the reverse taper on the piston seal land;

[mobilehomer]

The side that is down in your picture goes toward the piston. It is a tight fit going on, but should spin after mounting. In fact, twisting afterward is the way to make sure it is seated fully. I use a couple of 1/8" or smaller flat screwdrivers and work it on like you would a tire on a rim. Do NOT lube the mount stem!!
Some recommend heating the seal in hot water for a few minutes to make it more pliable. Take your time and watch your fingers!! Don't ask how I know.

[Roadworthy]

Ken uses the same seal installation method I do.  I have read that if you can find the appropriate size wire nut you can use it to work the seal onto the piston as well.

The only time the screwdriver trick has not worked for me was with the Vortek moly seals.  They are MUCH harder than a normal seal.  For them I put the piston and the properly oriented seal into a clamp and start tightening the worm gear.  I just threw that in because I don't know what seal you got.

[unionrdr]

The white one in the top pick is the new seal. Ditto on the material for the new breech seal. I thought the 2 screwdriver bit would be the answer. Close fit for my largest C-clamp. Clamp might not be big enough? And thanks for the warning on the lube. I'll wipe it off the seal land. Dang pita. I don't have a vice to use or someone to hold this dumb thing so I can have both hands free to use both screwdrivers.

[Buldawg76]

To get seal over the pistons flange I use either a 13mm or 1/2" socket that is just slightly bigger in diameter than the flange to push the seal over with some silicone grease. you can use the square end of the socket that the ratchet or extension would fit in to and force the seal over and then with the piston clamped in a vise with towels protecting the outer surface of the piston. Place the end if the socket tight against the flange on the piston with the seal in the correct orientation and while holding the socket against the piston with one hand use the other to evenly and quickly push the seal off the socket and over the flange in one swift fluid motion and the seal will pop right in place with no chance of damage to the seal. then just rotate to seat and your ready to go.

It works with any size seal if you use the correct size socket.

You may want to practice with the old seal a few time to get it down on just how to make it slip in place easily.

Mike

[TF89]

Use a electrical wire nut without the flanges.  I think either yellow or red color code.  It will just sit on top of the piston, slide the seal over that and the press down with either your fingers or a socket.  I could not find pictures of this anywhere on the net, yet that is how I first discovered it.  It is the fastest method I have found.

I found the link, it is about half way down the page.  He is using a yellow, size all depends on your seal ID.
http://anotherairgunblog.blogspot.com/2010_12_12_archive.html
It does not damage your seal and is awesome.

[unionrdr]

I looked at the link. I'll have to have my boys look through my tool box for the yellow nut. Neat idea to use a deep well socket to push with. Although the Diana seal ID looks smaller? Maybe use a rubber mallet?

[TF89]

It slips really easy, takes some pressure but nothing hard at all.  Once it starts moving, it just slips on.  As for sizing, it needs to match the od of piston seal holder.  Not sure what you call it. 

[unionrdr]

That's the tough part. But, with y'all helping me out, I will come up with something To work on these Trail's pistons/seal's! I also noticed nobody, not even Kenny shows how they get the new seal on the piston! I, however, will! I'm not greedy...just trying to help by figuring this stuff out for the DIY'rs out there. Let those that aren't mechanically-inclined send us their airguns for repair/restore/modding. I feel better doing it this way.

[SteveP-52]

All I've ever done was make sure everything is clean and grease free including the bench, set the new seal on the bench grooved side down, set the piston at an angle into one side of it, then just roll the piston forward and onto the seal. You have to press hard, but even my Vortek seals have popped right on with no problems and I've never had to use any tools to get the job done.

[unionrdr]

Won't work for me. Carpel tunnel and rheumatoid arthritis prevent it. I wish it were that simple.

[Privateer]

I don't follow you Leonard.

"Carpel tunnel and rheumatoid arthritis prevent it."

How the heck you manage to use 2 small screw drivers but can't do as Steve suggested?
I do it exactly as Steve does with one small extra step. I boil water and let the seals soften in that for around 5 minutes or so.
I had 3 fingers ripped off my right hand and reattached and have problems with that but still can do it.
The piston is a LOT larger then a small screw driver. And only takes 1 hand not 2.

[redtrucker610]

I heated mine with a hair dryer to get them good and soft. Then just popped them over the top of the piston. I never had trouble putting them on this way.

[Back_Roads]

 I wonder if a spring compressor could be modified to work as a piston seal installer ?
Or a similar device made to do the job.