Tuning HELP! Benjamin marauder .22 air pressure gone , air coming out of barrel

Jump to latest Follow Reply
S

stormyhorse

Member
Apr 16, 2020
6
0
colorado, United States
I purchased a wonderful used first generation Benjamin marauder .22 last year and it has been great but today I went to shoot it and after I pulled the trigger it started hissing and the air pressure dropped to zero. I had air coming out of the end of the barrel and also where the pellet is put into the barrel.
I am still very new to air guns and would love some insight on what broke and how I can fix it and what I'll need , keeping in mind I have never worked on a gun before, lol.
I have not yet shot a tin of pellets through it as I use it for livestock protection and need to get it fixed asap :)

Thank you for your help and time!
 
That symptom indicates a problem with the poppet (valve stem). Either the plastic part broke or a piece of debris got trapped in it. A bit of debris will usually result in a slow leak. If it leaked down in seconds, the part is probably broken.

It is Crosman part number 1700-140. Can order a replacement direct from Crosman's parts department or from Pyramyd Air.
https://www.pyramydair.com/product/crosman-exhaust-valve-for-marauder-rifle-pistol?a=7352

 
Upvote 0
Another option is to replace the valve itself with a Gen 2 and it is a direct fit. It has the upgraded poppet valve material, same as PA is offering. With a higher valve spring tension you will pick up an extra 10 shots or so. You will have to order it from Crosman.
Click to expand...


That is great to know and it sounds like the way to go, especially if I can get some more shots out of it as well :) .
 
Upvote 0
All but guarantee the leak is the poppet valve as was already discussed. Crosman parts pricing are very reasonable. Give them a call and ask to include a numerous quantity of the o-ring used to seal the valving, gauge port and filter inlet. The same o-ring is used in all locations which is convenient.
Click to expand...


Thanks, I called crossman and ordered the part and hopefully all the o-rings I'll need :) and that is nice to know that they use the same size o-ring in numerous places :) .

I am hoping I don't screw up anything when I take everything apart to replace the valve ;) .

Thank you for everyone's help!
 
Upvote 0
Stormy,

Sometimes when the gun is adjusted to higher velocities and power, the hammer spring can overpower the valve spring, and stay open after the shot, dumping the air in the cylinder. This can happen with an unregulated gun, once it gets down to lower pressures, and is common with guns tuned to the upper end of the power curve. Cock the bolt back, and then try to fill. If you are filling from a handpump, it may not have enough volume to reseat the valve. If this is the case, I would try to borrow someone else's air tank, to get a good shot of air into it, possibly seating the valve. If this is the case, there may not be anything wrong with the valve or poppet. The older Gen 1 guns had valves in them, that had a short lifespan compared with the newer, higher quality valves produced today, as well as their replacements.

If you deem that you must take it apart, here's a video from my YouTube channel, Field Target Tech that goes through the disassembly process. 



https://youtu.be/xzFlGbRGXtI





Here is a video on its reassembly 

https://youtu.be/60JdCRPTIlg





Tom Holland 

Field Target Tech 

Fieldtargettech.com 


 
Upvote 0
See if there is an industrial rubber and seal supply near you. I go to Industrial Rubber and Gasket in Alexandria LA and get o rings for pennies. Lay in a supply of the ones that seal up the main tube because if my experience with my Gen 1 you will be using them, a lot of them. Like Pruitt wrote above do that BStaley oring mod. I did and got a more efficient gun and flatter shot curve.
 
Upvote 0
You must log in or register to reply here.
Top Bottom
Back
Home
Forums
Resources
Menu