GTA
Airguns by Make and Model => Benjamin Airguns => Topic started by: BrianUSA1 on February 24, 2013, 05:44:01 PM
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Last summer I bought a Benjamin Titan GP (BW8M22NP) and had a blast with it >500 rounds. I was impressed with the power that the rifle had with a single stroke to charge it (vice the old Crosman bb guns).
This weekend I took it out and it appears the gas piston has died. The Crosman website does not have a schematic for the Titan GP but after disassemble it appears almost identical to the Trail NP. I can push in the ram with one hand, so I'm assuming the seals went bad. Can someone tell me if the gas ram and piston seal are interchangeable between these models?
Also, are there any other seals I should change or performance mods that you might recommend while i have it apart?
Finally, I've read some posts about lubricant issues and it seems that silicon grease is the recommended lubricant for the piston. Please advise if there is something better.
Thanks!
Brian
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I have the EVP from Crosman's website. Benji Titan and Crosman Titan are the same. PM me if you cannot find it in the downloads section of the customer service page.
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Yep they are the same. While you have it open, check the piston seal and make sure there are no nicks or chunks torn out of it. If so order a new one from Crosman. Before installing make sure to file all the sharp edges of the chamber cutouts so that the new seal doesn't get damaged when installing it.
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This is a followup post for others to reference in case they need to replace the gas piston on the same model air gun.
I ordered the parts (Gas Spring and Piston Seal) using the Trail NP parts numbers and the were a match.
I ran into one issue on reassembly. The symptom was that the trigger sear would not latch into the cylinder. I could not figure out why and I sought advice from some members in the Chat room. Their advice was to disassemble and try again - apparently this is not uncommon for folks working on their air gun for the first time.
After taking the gun apart, I found that the Gas Spring was not fully seated in the "Back Spring Guide." The "Plain Plate" was loose, you could hear it rattle around, and I had to put a punch through the hole in the Back Spring Guide to tap out the plate and unstick the base of the Gas Spring. The replacement Gas Spring was just slightly larger that the original part, despite having the same part number painted on it. I sanded the black paint off the end of Gas Spring, sanded the inside of the Back Spring Guide, cleaned up and applied a bit of moly grease and the Gas Spring then fit fully into the Back Spring Guide.
Reassembled and it works great! Better than new. At this point, I have to assume that it was not working properly out of the box from WMart.
I hope this information will be helpful to someone down the line who is looking to repair their Titan GP.
Thank you to the folks on the forum and on the chat that offered advice.