Power Tube Tip Oring

[Advanced]

Anyone know the size of the power tube tip oring?

I rebuilt a valve, this one just crumbled apart. Not included with the agd parts kit.

This is for classic valve if that matters.

[Hobbes]

Is it not a 010? That should be in an AGD parts kit I would think.

[Toestr]

Yes 010.

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[Alexndl]

I have used in the past standard black 010 oring at 70 duro and it worked but if you want the original AGD OEM parts you can check for 010 urethane oring (translucent) and I think they are 90 duro

[Advanced]

I am referring to the tip, not the power tube shaft oring.

This is on the brass cap, part 781

[Alexndl]

They are the same size
I usually use standard black oring 010 and 070 duro

[Sharkytrav]

I literally just now successfully replaced this after a long long battle. That was almost as bad as replacing your first JT lens, hate it. 3 more to go, Jibbers.

[MrBarraclough]

Oh, that bastard. I know exactly which o-ring you're talking about. Inspired me to finally go buy some snap ring pliers. Put the power tube tip in a vise and use two sets of snap ring pliers (or one set and a needlenose you can easily push open) to stretch that sumbitch into place.

[Toestr]

I literally just now successfully replaced this after a long long battle. That was almost as bad as replacing your first JT lens, hate it. 3 more to go, Jibbers.

Have you tried cutting the old ones with a razor?

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[Sharkytrav]

Have you tried cutting the old ones with a razor?

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The old one crumbled off, well kind of goo'd off. The larger on/off o-ring was blue and stuck to the on/off topper deal, if that gives you an indication of the condition of these o-rings. I bet that says something specific about the lube used in this valve but not sure what. Anywho, old stuff was the was the easy part. Most of the other rings were piece of cake. This power tube tip though... what a beast!

[Jordan]

I literally just now successfully replaced this after a long long battle. That was almost as bad as replacing your first JT lens, hate it. 3 more to go, Jibbers.

Pffft... try changing banjo bolt orings on a classic RT. You'll wish you were changing a PT tip oring. 🙂

[Sharkytrav]

Hah! I read the RT post recently. Good stuff. I didn’t follow the recommendations about soaking in oil.

[tunaman5]

It is NOT a #10. A #10 is the powertube /on/off oring. The powertube tip is bigger and is not in the parts kit. This is an oring that you almost never have to change.

[Spider!]

I have this memory of the automag video where Tom says the PT tip o-ring is non-critical and can be used to replace any of the other three 010 rings that are critical. I've always thought the PT o-rings where just stretched out. It could be my imagination at this point.

[Jordan]

So... what do we use when we have a 20+ year old Automag that DOES need one?

[MrBarraclough]

Like Spider! my recollection is that the PT tip oring must be the same size precisely because it is listed as a source for a field-expedient replacement should one of the more critical orings fail. It just feel like it ought not to be the same size because getting that sumbitch into place is so damned difficult.

[maggot]

That o-ring serves the same purpose as the one on an Autococker IVG - it's there solely to keep the part from un-threading itself.

[MrBarraclough]

Edit: The PT tip o-ring is apparently NOT 010, which explains why forcing a 010 into that role is so difficult.

It is an 010 and therefore included with the kit (90 duro urethane). Just such a royal pain in the ass to install that you'll swear you've got the wrong size. Practically impossible to get on with fingers alone. I had to use some needlenose pliers (awkwardly pushing them open with the backs of my knuckles) and a small flathead screwdriver to stretch that bastard over the power tube tip. Immediately went out and bought a snap ring plier set for the next time I have to wrestle with the damned thing.

As others have pointed out, it is there just to prevent the powertube tip from coming loose. <strike>The only reason AGD used 010 urethane was for redundancy with other seals.</strike> If you can get a 011 or 012 buna oring on there and it still provides enough tension on the threads, it shouldn't hurt anything. You just won't be able to use it as an emergency spare for one of the other 010 urethane seals.

[tunaman5]

It is an 010 and therefore included with the kit (90 duro urethane). Just such a royal pain in the ass to install that you'll swear you've got the wrong size. Practically impossible to get on with fingers alone. I had to use some needlenose pliers (awkwardly pushing them open with the backs of my knuckles) and a small flathead screwdriver to stretch that bastard over the power tube tip. Immediately went out and bought a snap ring plier set for the next time I have to wrestle with the damned thing.

As others have pointed out, it is there just to prevent the powertube tip from coming loose. The only reason AGD used 010 urethane was for redundancy with other seals. If you can get a 011 or 012 buna oring on there and it still provides enough tension on the threads, it shouldn't hurt anything. You just won't be able to use it as an emergency spare for one of the other 010 urethane seals.

It is NOT a #10. And it is NOT included in the parts kit. Know of what you speak of...The powertube oring is a AGD#123 and the Powertube tip oring is AGD# 781. It would be almost impossible to install a #10 on there as it is way too small. Snap ring pliers for an oring? Better go back to apprentice school.

[MrBarraclough]

Snap ring pliers for an oring? Better go back to apprentice school.

Well good morning to you too, sir.

So they are two different o-rings that are easily confused by someone who assumed that the parts kit would contain examples of all o-rings in the marker. Good to know. Explains why it was so damned hard to get it on there. Looks like I misremembered where the manual says you can reuse orings as field-expedient spares for the power tube oring. I had thought the PT tip oring was on that list, but apparently it is just the two urethane on/off orings. That's why I thought the PT tip was deliberately the same for redundancy.

[Jordan]

It is NOT a #10. And it is NOT included in the parts kit. Know of what you speak of...The powertube oring is a AGD#123 and the Powertube tip oring is AGD# 781. It would be almost impossible to install a #10 on there as it is way too small. Snap ring pliers for an oring? Better go back to apprentice school.

Got a size then, Tunaman? Does AGD sell them? Can we source them somewhere else if you or AGD does not stock them?

[superman]

http://www.airgundesigns.com/product-p/000781.htm

[Jordan]

Thanks!

That helps.