Vantage NP dead. Bad nitro piston?

[TheWaterbug]

I hadn't used my 6-yr-old Crosman Vantage Nitro Piston since October, and when I took it out yesterday, it was completely non-functional. The cocking force is about 1/4 of what it's supposed to be, the gun does a weird twangy thing when I pull the trigger, and the pellet doesn't move.

Is this the sign of a failed nitro piston? Is this a fairly straightforward repair? 

Suggestions for a replacement part?

Thanks!

 

[brian_null]

Maybe this will help...

https://support.crosman.com/hc/en-us/articles/203927400-How-do-I-order-parts-online-

 

[Windmill01]

Either you have gained exceptional strength since October or your ram has failed. Look up the part number on the info Brian has given you and purchase a new ram. Easy to install but you will need a spring compressor. Look up the net for info on rebuilds.

Gary

 

[TheWaterbug]

Thanks! Looks like the bad part is BT9M22-00-5A. Searching Pyramid for that part returns their aftermarket ram, their part number PY-A-3830, for $50, which is less expensive than the Crosman OEM part. Should I also replace the piston seal while I'm at it? Anything else I should do?

I googled "nitro piston replacement" and found this alternate method:

https://www.youtube.com/watch?v=4JQXmqa2Uj0

using a clamp that I already have. Has anyone used this alternate method? Is it as easy as it looks?



I've never disassembled an airgun before, so I'm not quite sure what I'm getting into. And the parts are more than half the price of a new gun. But I hate throwing things out, especially if they can be fixed. 

Thanks again!

 

[TheWaterbug]

Hmmm. Here's another aftermarket piston for ~$34, including free un-tracked shipping from Australia.

It says it's a replacement for "BT9M22-00-5", but I don't know if that means it's also a replacement for BT9M22-00-5A <-- with the "A" at the end. Does anyone know if these are compatible?

Apparently this looks like the same part that's sold on the manufacturer's regular website for $53 with free un-tracked shipping, or on amazon for $60 + $5 shipping. 

Has anyone bought from these folks before? Are they legit?

 

[RWSx3]

I replaced a weak NP a few years ago in a Nitro Venom, ordered direct from Crosman, kept the receipt, it is the BT9M22-00-5A. I ordered 2 of 'em at the time, thinking I may need another down the road. Prices have gone up (doubled) since I needed mine....paid $26 each with $4 ship...…..there's those Chinese tariffs workin' for us

Back to the install. It's not a big job, your clamp should / will do the task, since your original NP has lost its' charge, you may only need the clamp for re-assembly and re-inserting the pin once the new NP is in. 

There's a few helpful tips that will make your re-assembly job easier..... Once dis-assembled - on the compression tube, you will notice cut-outs, (cocking arm, etc.) they have SHARP edges, smooth those edges with emory cloth, sandpaper on a dowel stick - this helps keep your NEW seal new when re-inserting the piston..... CLEAN the compression tube well using degreaser - dry thoroughly then re-lube LIGHTLY, moly paste, synthetic grease, again LIGHTLY. Piston install - slight pressure on the seal lip at the cut-out areas using a small flat screwdriver will allow easier piston insertion. Install the new NP , re-locate cocking arm and you should be ready to clamp it down and pin it.

Good luck.

 

[Windmill01]

Send Laurie an email at Customseal Australia he is very helpfull and will answer all your questions. I’ve bought rams,piston seal and pivot washers from him. No worries at all. I’d order a new piston seal as well.

Gary

 

[TheWaterbug]

Hmmm. Here's another aftermarket piston for ~$34, including free un-tracked shipping from Australia.

It says it's a replacement for "BT9M22-00-5", but I don't know if that means it's also a replacement for BT9M22-00-5A <-- with the "A" at the end. Does anyone know if these are compatible?

I sent a message to Custom Air Seals in Australia about compatibility, and they responded: 

Yes it should fit, but to make sure compare the listed measurement to the ram in the gun

The ebay listing has these specs/measurements:

260MM TOTAL LENGTH

150MM BODY

110MM SHAFT LENGHT

8MM SHAFT

60KG 600N MIN

but I can't find any for the Crosman OEM part. The Crosman parts list just has a part number and a drawing with no dimensions.

 

[Windmill01]

You will need to take it apart and measure your ram, no time like the present. Doing this will give you time to smooth out the sharp corners and throughly clean the chamber etc. Custom also sells Molly paste and as RWS*3 mentioned use it sparingly. Don’t get any on the front of the piston seal. Have fun and let us know how you go.

Gary

I just went out to my shed as I remember that I have two spare rams for my Benjamin Titan. Both are the same measurements as you quoted. So if the part number for your ram is the same as mine your in business. 

Stop the press I just looked up the part number for my Benjamin Titan gas ram and it’s the same as what you quoted and seeing that the measurements are the same you are in business.

 

[TheWaterbug]

I googled "nitro piston replacement" and found this alternate method . . . using a clamp that I already have. Has anyone used this alternate method? Is it as easy as it looks?

Yes, it is! The size of the socket doesn't have to be 14mm; anything between 10 and 15mm would work. But the bar clamp has to be able to open to at least 17" between the pads, to get around both the that flat part of the barrel assembly and the socket:

But once the clamp is in place, one squeeze, and the pin just drops out. Here's my bad gas ram:

I can compress it fully with my hands. I'm assuming that's bad, as I can't apply nearly 60 kg of force to it. The total length is 10 1/4", or 260mm, the body is 150mm, leaving an expanded shaft length of 110mm, and the diameter of the shaft is 10mm. Diameter of the body is 18mm:

This all matches the Custom Air Seals specs except for the smaller shaft diameter of 8mm. Is that going to be a problem? I took this photo down the compression tube assembly, and it looks like the shaft just inserts loosely into a milled-out cavity in the piston (the out-of-focus part, right in the center):

It seems like a smaller shaft would center itself in there, and I don't see any seals that go around the shaft itself.

Should I take a gamble with the Custom Air Seals part? Or should I pay the extra $18 for the Crosman OEM part?

 

[Windmill01]

I have different size shafts in my Titan, no issues at all. I would also order a replacement piston seal and a little tub of molly from Laurie at Custonairseal should you decide to purchase from him. The piston seal in my Titan is 25 mils I recall. I think yours would be the same but I’d measure it just in case.

Gary

 

[TheWaterbug]

Hmmm. Here's another aftermarket piston for ~$34, including free un-tracked shipping from Australia . . . . Apparently this looks like the same part that's sold on the manufacturer's regular website for $53 with free un-tracked shipping.

I'm an idiot. Their regular website has its pricing in kangaroo dollars, so it's the exact same price as on ebay.

So now I can add the moly paste and piston seal to my cart, on their regular website.

Is this the correct seal for a Crosman? 

 

[Windmill01]

 

These are the seals I’m using from Customairseal.com. The blue one is the one you have in you picture. Somehow after a few months shooting with it the seal developed a hole on its face and accuracyf diminished. If you go to the web site Customairseal.com and hit the shop button you should be able to place all you need in your cart.

You can also use the other seals I have included in my photo. I think the $53 is Aus money, maybe send him an email seeking clarification.

Gary

 

[TheWaterbug]

Somehow after a few months shooting with it the seal developed a hole on its face and accuracyf diminished.

That's so strange! Any theories on how that happened?

 

[Windmill01]

My theory is that the exhaust port may have caused the hole.

 

[TheWaterbug]

My theory is that the exhaust port may have caused the hole.

"It's a small thermal exhaust port, right below the main port."

This one? 

 

[Windmill01]

You guessed it. I would say it is from the piston hitting the end of the chamber. Have you decided what you are going to order. When I fit a new seal I smear a light coating of silicone oil around the edge of the seal prior to sliding the piston into the chamber. Make sure there is no silicone oil on the front of the seal.

Gary

 

[TheWaterbug]

Not yet. I haven't had time to disassemble the gun fully, to inspect and measure the existing piston seal. Removing the gas ram was comparatively simple. I'll have to pull up another YouTube video to guide me through the disassembly procedure, to make sure I don't make any rookie mistakes, like causing an e-clip or spring to go sproinging off into the sofa cushions.

But I also got impatient and bought myself a Crosman F4 from Wal-mart, for $79 plus tax and free shipping. It arrived the next day. Unbelievable. 

I will probably still spend the ~$60+ for a new gas ram, piston seal, and moly paste to fix the old Vantage, because I hate wasting stuff. But it boggles the mind how a new gun is almost the same price as just a few replacement parts. 

 

[Windmill01]

That’s cheap if you were to buy one in Australia it would probably cost around $300 US. I recall about 5 years ago my Titans cost around $450 Aus each.

 

[TheWaterbug]

Yup! That F4 uses the same gas ram as my Vantage, so you could almost purchase it just for parts value!