HW95 piston damage

[thomas9784]

Hi guys,
Just before fitting my ww kit into the 95 I noticed some wear on the piston near the seal I wasn't to worried as its nearly 22 years old. I've been using the rifle and its sweet to shoot I cant put it down. I recently tried fitting an Aussie red piston piston seal and upon assembling found it and extremely tight fit. 5 test shots were superb until I cocked the rifle again and it had the roughest cocking stroke, l though crap its got to be the new Weihrauch cocking shoe so had it apart again and had a look then fitted the old shoe to check. I assembled then cocked again the stroke was exactly the same rough as a badgers nothing to do with the shoe. Took it down again fitted the old seal and was sweet again, shooting lovely. It didn't like that red seal, I've been shooting without incident for about 300 shots and today noticed the stroke starting to get a little rough halfway through the cocking stroke, I stopped took it home and had the rifle stripped again, the wear has spread on the piston a bit more that last time and is concentrated near the base of the piston seal. Inside the cylinder from what I can see there's some light scoring. I degreased, cleaned thoroughly, lubed and reassembled. Cocking is smooth and firing cycle is spot on again. Anyone experienced this? Or can help with a solution.

[tinbum]

Debur, polish and, if possible, radius the leading edge of the piston. If the aftermarket seal put pressure on the piston in one direction it may have started the issue. Remove all chance of it "digging in" again for peace of mind.

[thomas9784]

Debur, polish and, if possible, radius the leading edge of the piston. If the aftermarket seal put pressure on the piston in one direction it may have started the issue. Remove all chance of it "digging in" again for peace of mind.

Ive deburred polished the piston and chamber etc do you think maybe get it banded or buttoned?

[tinbum]

Ive deburred polished the piston and chamber etc do you think maybe get it banded or buttoned?

If the problem returns then you may have to, but I shouldn't think it will be necessary.

[thomas9784]

If the problem returns then you may have to, but I shouldn't think it will be necessary.

Cheers mate.

[venoman]

Weihrauch pistons are very soft .

[Spitzer]

thomas9784, you have a lubrication problem with your gun. Caused by either lack of it or the wrong type.
A lot of people apply the wrong grease, and some moly greases are not what they are made out to be, but there is one that is the king of lubes for airgun metal to metal piston lubrication, and that is ABBEY's Moly G-n Paste.
A small pot of G-n Paste will lube many, many airguns and give a very smooth feel to the cocking cycle and trouble free performance for thousands of shots.
Abbey recommend buffing it into the metal surfaces, but I also apply it wet to the rear of the piston, rear end of cylinder, cocking slot and barrel pivot bolt and shims and also to the barrel detent
on break-barrel guns.
Hope this helps.

[lensman57]

thomas9784, you have a lubrication problem with your gun. Caused by either lack of it or the wrong type.
A lot of people apply the wrong grease, and some moly greases are not what they are made out to be, but there is one that is the king of lubes for airgun metal to metal piston lubrication, and that is ABBEY's Moly G-n Paste.
A small pot of G-n Paste will lube many, many airguns and give a very smooth feel to the cocking cycle and trouble free performance for thousands of shots.
Abbey recommend buffing it into the metal surfaces, but I also apply it wet to the rear of the piston, rear end of cylinder, cocking slot and barrel pivot bolt and shims and also to the barrel detent
on break-barrel guns.
Hope this helps.

What is the difference between this and the LT2?

A.G

[thomas9784]

I believe im lubing correctly with moly from bisley and Ive never had a problem.

Is the LT2 lithium based with moly.

[lensman57]

I have checked Abbey's site and that particular paste is not listed or I couldn't see it. All there is, is the SM50 and the LT2. I used to have some Rocol paste from a few years back which I used for model engineering but when I checked the price today it was over £50.00 for a tube and £150.00 for a tin. Thanks but no thanks.

A.G

[thomas9784]

[rancidtom]

Abbey stopped making the GN paste some years ago, the Rocol 65% moly paste is very expensive.
Many moly greases are quite low percentage moly, the higher the percentage the better for airgun pistons and cocking links but it's hard to find and expensive.

[bighit]

There was a guy on here that bought a tub of rocol stuff and sold small tubs of it to members on here.

[FPoole]

If you haven't already, I would slightly radius the shoulder of the piston, where the base of the seal sits. Honda used to sell M-77 assembly paste in tubes. I think it was intended for brake calipers and is made by Dow Corning with a 77% moly content. Very good stuff for stopping metal to metal wear. I've used it and Maccari moly paste on my TX's for years.

[Mark A]

I have checked Abbey's site and that particular paste is not listed or I couldn't see it. All there is, is the SM50 and the LT2. I used to have some Rocol paste from a few years back which I used for model engineering but when I checked the price today it was over £50.00 for a tube and £150.00 for a tin. Thanks but no thanks.

A.G

You can sometimes pick it up on the bay for £20 for a 100g tube. Still very expensive though. I think there are cheaper alternatives out there, you just need to check the moly content to make sure its the good stuff.