Need help with a Theoben Crusader Gas Ram

[nitris223]

Anyone here ever remove the gas ram from a Theoben Crusader.  I believe I have a metal chard right behind the piston near the top of the receiver tube. I can see a scrape mark just to the side of the piston rod. Do I have to depressurize the gas ram to take it out or will a spring compressor work .  I don't want to ship it 2000 kms just to get the piece of what ever it is out unless I have to.  I can find very little information on the internet about the Crusader.  Mostly the Eliminator and it has a different set up for piston seals.  Maybe they are the same for tearing down. 

[Nikoman]

I wouldn't mess with it since it has the H.E. system like the Eliminator/Crow Magnum. It's a higher pressure than the older system which they use in the HW90/RX series rams. However, if you have a way of refilling it with an HE pump - then go for it. I would let the air/gas out before working on it so you shouldn't need a spring compressor.
Is the gun still performing well?
The Crusader looks to be a full power magnum which probably shares a similar setup with the Eliminator. I'm guessing the seals are different.
Can you snap any pics of the area you're describing?

[nitris223]

Nikoman.  It is to hard to get a picture. If you look through the cocking slot it is just visable at the right angle . If you were looking at the back of the gun it would be in the 10 maybe 10 oclock position. 

I think the Eliminator has o-rings for seals and the crusader has something else.  There are no pictures out there that I can find as to what it looks like. 

One thing I did discover today was that if I cocked the gun slow, it shot inconsistent FPS. From 680 to 720 and everything inbetween.  Then I was getting a little frustrated and I guess I was cocking the gun a little more aggressively, more like a quick sweep.  Then all of a sudden it shot 3 10 shot strings and they were 722to 727, 719 to 726 and 720 to 728 .  I then tried 5 slow and 5 fast to prove to myself that I wasn't going crazy and sure enough 5 up and down and slow and then 5 higher fps and consistent..

Still shoots accurate at either speed .  I guess after shooting 350 pellets the day before and then finding my arm sore today I must have been cocking it to slow.   Not that it makes any sense begause it is a charged air piston.

If you shoot your Eliminator over the chrony try slow cocking and then fast aggressive cocking and see if you find a difference.  If it is possible on the Eliminator. I hear they are harder to cock then the Crusader.   I have to take a break from the Crusader for a few days and let my arm get better.

[Nikoman]

Sounds like it's consistent.
Is it still under warranty? If so I'd definitely send it in while it's still covered.

I should try a quick stroke with the Eliminator to see if the velocity numbers change, it's possible with a good balanced breakfast The cocking effort isn't nearly as bad as it's made out to be, trust me.
The cocking effort on my Vulcan is almost as brisk as the Eliminator since it's a carbine. It was recently gas rammed but the effort didn't change much, it was always on the brutal side.

As far as the insides go, the Crusader is probably the closest relative of the Eliminator so I would assume the parts are nearly identical. I'll have to take a close look when I return home this weekend and let you know what I see in mine through the cocking slot. I've never opened mine either, I wouldn't dare open this beast

What caliber is your Crusader? I'm assuming .22, right?

I guess after shooting 350 pellets the day before and then finding my arm sore today I must have been cocking it to slow.   

I have to take a break from the Crusader for a few days and let my arm get better.

I'm still LMBO about this one!!

There were days when I shot my Eliminator about 300-400 times in a day. I know this because of the Chrony numbers and dates, targets with dates/times and the number of tins I went through in a day. I'm so used to it that my arm never gets sore anymore.

Hey, I would love to see some pics of that awesome rifle. Can you post some?

[h2rider]

You will need to depressurize the ram before disassembling a Crusader.  There is a small plug with a hex socket at the rear of the receiver.  There will be a schrader valve under the plug.  Depress the valve stem to release the pressure, just like a bicycle tire.  Once the pressure is gone you can safely disassemble the action.

The Crusader uses a conventional synthetic piston seal just like an R1/R9/HW30/etc.

Either a Theoben-specific pump or a conventional PCP pump with the proper threaded adapter will be needed to recharge the ram.  I think the max. pressure is either 30 or 40 bar (420 or 560 PSI), probably the lower value.  The best way is to start low and work up to your desired velocity.

Paul in Liberty County

[nitris223]

[
There were days when I shot my Eliminator about 300-400 times in a day. I know this because of the Chrony numbers and dates, targets with dates/times and the number of tins I went through in a day. I'm so used to it that my arm never gets sore anymore.

Hey, I would love to see some pics of that awesome rifle. Can you post some?
[/quote]

I am still getting use to the Theoben 22 cal.  It is alot stiffer then other break barrels I have shot.  Just for a test I pulled out the Crosman Nitro Venom I have to see if it reacted the same way with the gas ram.  Didn't show any difference on that one.  But the first time I cocked it I though I was going to fold it in half and snap it off.  That thing was so easy I just sat there and laughed to my self because it happened so quick.  One thing I do know is that I can't shoot that crosman anymore, it just feels so akward in my hands. It doesn't feel comfortable to shoot at all.  I am amazed I could shoot 3/4" at 30 yards with that before .  It's up for sale.

As for warranty , there is none. I bought it used and it is over a year old.  Don't get the 10 yr warranty here in Canada so they say.  If I could get my hands on a pump for a good price I would sure buy one . I really don't want to send it 2000 kms for service when it is needed.  Also where would I get some piston seals.  The guy here in Canada doesn't stock them.  My luck I have to order it from the U.K.  I would sooner service it my self then I know who to blame when something is not right. It could take a month for turn around time when I have to ship it away.

[Nikoman]

That thing looks like a heck of a shooter!! WOW!
Nice groups too

I would contact David Slade from Airgunwerks down here in the USA. Hopefully he can sell you any seals or parts you may need. Just do a google search for him and you can't miss. Shoot him an email (no pun intended) and ask if he deals with our friendly neighbors like you up North. He is the importer for Theoben USA and besides that, he is the most knowledgable guy about those guns. He would know the Crusader and what parts, etc..
He would be the first line of support I would try since it's not under warranty. You shouldn't have to ship your gun 2,000km away. Definitely try and find an H.E. pump for that gun. The Disco pump seems to work for the HW90/RX series rifles but I don't know if it works for the H.E. system - that's a whole different game. But whatever works for the Eliminator, should definitely work for the Crusader.

Thanks for sharing those pics. That is a gorgeous walnut stock that Crusader is wearing! That's the perfect caliber for that gun.

[Cliff]

I recently spoke to the repair guy who did the ram rebuiuld on my HW90 Theoben. He discharged the thing.
I imagine that it'd be a real bear to handle without  doing so - if it's possible at all.  It is charged again after it's all back in the gun.

[nitris223]

I got to get my hands on a pump soon.  There is something inside the receiver tube that makes the gun grind on the cocking stroke.  Sometimes 50 shots and other times 250 shots.  I can't find it what ever it is.  I even put one *(&^ of a strong magnet on the outside hoping it would pick it up but no luck, it did the grinding thing again today. A dab of moly and it's good to go again. Needs to be stripped down to make sure.   Now to keep my eyes out for a Hill pump or something like it and then I will get it in my head , well you have the pump might as well buy a PCP.  That's all I need, another one to tinker with. 

[clip]

That thing looks like a heck of a shooter!! WOW!
Nice groups too

I would contact David Slade from Airgunwerks down here in the USA. Hopefully he can sell you any seals or parts you may need. Just do a google search for him and you can't miss. Shoot him an email (no pun intended) and ask if he deals with our friendly neighbors like you up North. He is the importer for Theoben USA and besides that, he is the most knowledgable guy about those guns. He would know the Crusader and what parts, etc..
He would be the first line of support I would try since it's not under warranty. You shouldn't have to ship your gun 2,000km away. Definitely try and find an H.E. pump for that gun. The Disco pump seems to work for the HW90/RX series rifles but I don't know if it works for the H.E. system - that's a whole different game. But whatever works for the Eliminator, should definitely work for the Crusader.

Thanks for sharing those pics. That is a gorgeous walnut stock that Crusader is wearing! That's the perfect caliber for that gun.

  Soon after I got my Theoben Evolution, it developed a  problem. It was cocked and  loaded but the safety wouldn't release. I spoke to David Slade at Airgunwerks. He guessed it had a bent safety lever and suggested I send it to him. He had it fixed in no time.  What I'm saying is.. he's the guy to go to with any problems concerning Theobens.

[Nikoman]

  Soon after I got my Theoben Evolution, it developed a  problem. It was cocked and  loaded but the safety wouldn't release. I spoke to David Slade at Airgunwerks. He guessed it had a bent safety lever and suggested I send it to him. He had it fixed in no time.  What I'm saying is.. he's the guy to go to with any problems concerning Theobens.

Yeah, he's the man for anything Theoben-related. I can't say enough good things about him, a true gentleman to deal with and he knows his stuff.

[nitris223]

Well it has to be stripped for sure now.  I was shooting last night and it came to a grinding halt.  I will be trying to get a hold of David Slade on Monday.  Need a pump and seal kit for sure.  There is something under the backside of the piston that is causing the problems.    Anyone know of a used pump for sale. 

[Nikoman]

Any news on your Crusader?

[nitris223]

Just to update even if it is almost a year later.  Got in touch with a guy at Rapid air works or something like that. I think the guy is Martin Ruttherfurd ( spelling)  Described the situation to him ordered the parts needed and did the repair myself.  Gun is back to shooting great.  Had a PCP ordered in the meantime so I had the pump to refill the gas ram. Not that bad of a job to do if you have the tools necessary.  Since I repaired it I have been controlling some pigeons at our local grain elevator. Picking them off the top of the grain elevator no problem. 

[cnjl3]

Did you replace parts without bleeding your gas ram?
When my Theoben Crow Magnum gas ram was resealed by David Slade I asked him if it was a good idea to adjust the velocity up and down like many folk seem to want to do. He said that when he filled my gas ram he used nitrogen and that he recommended that I just leave it alone. He said if I needed a less FPE airgun to just get another airgun. Seemed like good advise to me. So I have just left mine alone. One of my Beeman Precision Airgun Guides says that the H.E. system on my Crow Magnum gas ram is charged up to 900PSI.

[Nikoman]

Wow!
Thanks for the update, nitris.
Nice to hear you got it up and running.

Carlos,
it sounds like he did let the gas out before working on it to make it easier (and safer).
You can use a pump to fill it with regular air, nitrogen will make the cocking effort easier but in his case the Crusader isn't as much of a beast like the Crow Magnum.
I've always wanted to try one of those Crusaders, nice looking rifles and I bet they're really smooth.

[nitris223]

I used my Hill pump to refill the gas ram. Don't remember offhand what Martin told me the correct pressure was. But I filled it to what he said and used a specific pellet and then shot it over the chrony to verify if I needed more or less air. I was in the ball park on the first attempt and left it alone.  It has a sharp thump when I touch it off. I think I picked up 50 fps with the rebuild. Something tells me it is shooting 820 fps  with 16.2gr pellets. I could be off on the fps.  Been a while since I put it over the chrony.  All I know is that it works like it should and pigeons don't like it.

[johnnail]

do you think this pump would work?
  http://www.everestgear.com/scshpupro.html

[Nikoman]

do you think this pump would work?
  http://www.everestgear.com/scshpupro.html

I'm not sure if it would work, you might try calling Straightshooters (they used to sell the adapters when they sold the Theoeben gas strut rifles). You can show them the link and see what they say and they might have the needed adapter to fit the Theobens.