TargetTalk

The team I help coach has two Pardini K60's we don't use anymore. Before selling them, I tried to check them out, but the O-ring that seals the cylinder to the pistol is dead on all 4 cylinders.

I tried to find the part number, but Pardini doesn't have a diagram that shows the cylinder parts. Pardini USA has several O-Rings listed:

576/0/03 CYL. BODY VALVE EXT. O’RING

576/0/04 CYL. BODY VALVE INT. O’RING

576/0/06 CYLINDER VALVE O’RING K60/K90

None of these sound quite right, and Pardini hasn't responded to my emails.

Anyone know if one of these is correct? I'm guessing the first one, but I'm far from certain.

Thanks!

Take one off. Go to Ace Hardware. Look at the metric rings. Pick the closest ones. They're dirt cheap.

I'd rather get the real thing if possible. The best O-rings for CO2 are made from urethane, which doesn't absorb the gas nearly as much as the standard Nitrile material. If you use hardware store O-rings, they will shred themselves fairly quickly if you leave them under pressure, and then release the pressure abruptly (like unscrewing a cylinder). The Pardini O-rings are pale, which is most likely urethane.

I've lost count of the number of standard black Nitrile O-rings I've replaced in Tau-7's from just this issue.

Does this help?

http://airgunz.altervista.org/Esplosi/P ... sploso.gif

Lenny wrote:Does this help?

http://airgunz.altervista.org/Esplosi/P ... sploso.gif

Nope. Been there, done that...
It only shows the complete cylinder assembly, with none of the individual cylinder parts called out separately

The cylinder is # 576, and the component parts are # 576/0/01, 576/0/02, etc.

I have to laugh because I remember back in the day.....

A friend of mine was the biggest Pardini dealer in the U.S. With every gun he sold, he would change out the O-rings for U.S. made ones.

He went to Italy to visit the factory and took with him a large sack of O-rings from the Long Island aerospace industry. (Challenger grade!)

Unfortunately for us, he moved on to bicycle racing.

OK, but were they hardware store Nitrile, or something fancier? I had a Walther CP-1, and it used urethane o-rings & I never had a problem

Many O-rings applications are fine, but the cylinder seal O-ring on a CO2 pistol can have issues if the wrong material is used.

You are talking about the white o ring right? I have been slowly selling these pistols that I had when I coached a RTOC unit. The white o-ring is a harder plastic and not a rubber one. I find usually a little non petroleum lube helps reseal this ring. Having all 4 go bad seams a little unusual. I will check and see if I have any extra left. I have 3 air pistols left and various O-rings left also.
Ted

Ted wrote:You are talking about the white o ring right? I have been slowly selling these pistols that I had when I coached a RTOC unit. The white o-ring is a harder plastic and not a rubber one. I find usually a little non petroleum lube helps reseal this ring. Having all 4 go bad seams a little unusual. I will check and see if I have any extra left. I have 3 air pistols left and various O-rings left also.
Ted

Thanks! It's been a while since I tested them, but at least one O-ring looked cracked. They've sat in a safe for at least 6 or 8 years, and it could be twice that long since they were in active use.

I'll inspect them more closely & try some lube if they look OK. At this point, they are all empty, so I'll have to take them to where we have a CO2 tank first.

I cleaned & lubricated the O-rings on all 5 of our cylinders. Only two cylinders sealed well enough to get any CO2 into them. Of those, only one would seal on both pistols. The pistols work fine, I just need to fix the cylinders. You can see cracks in a couple of the O-rings, and they are hard. Getting them out without scratching up any of the seating surfaces will be tricky. I think I will make a brass hook to try to pry them out.

As luck would have it, I found a fossilized O-ring in a small bag of parts. It was stiff as a board, and I suspect it would break if i tried to install it. I carefully measured it, and it came out with some odd dimensions if I used metric. I switched to English, and Bingo!

The O-ring is a PERFECT match for the actual dimensions of a 1/2" ID x 3/32" width SAE AS568-112 O-ring. I checked on McMaster Carr, and another miracle occurred. They actual have them in polyurethane! Part # 9558K544, $10.48 per pack of 5. Pardini wants $4.77 each for theirs (if you can figure out which one to order).

http://www.mcmaster.com/#9558k544/=1230h3a

These are high durometer (extra hard), abrasion resistant O-rings, and they are even in the same cream color as the originals. They should work great as replacements.

Sounds like you have the problem solved however you may be interested in this old file of mine.

Ray

I have a K60 and when I was looking for replacement seals I had a hard time finding them. I finally got them from Tim McMurray at: http://www.mac1airgun.com/ . He was very helpful and reasonable. I don't have the size handy but that is where I got them.

Scott

Raymac wrote:Sounds like you have the problem solved however you may be interested in this old file of mine.

Ray

Thanks! That will be very helpful. All five cylinders filled OK, but one of them leaked when I installed it on the pistol. When I removed it, the cylinder valve didn't seal, so it needs rebuilding..