I see these threads and comments about various gas ram springers losing their pressure. How are these refilled? To what sort of pressures?
N/A Refilling a gas ram
- Thread starter Billinoregon
- Start date
some are made to refill or better yet to change the power to fit the pellet.
, but some are not refillable .
, but some are not refillable .
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I know most of the Hatsans can be refilled, I have no personal experience but just from seeing videos. Airgun Detevtives (JC) may have a video on it, or you can email him and ask. I know he has done it on the Hatsans, if that helps.
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Theoben and Hatsan are the only 2 I know of that can be rebuilt/refilled. Hatsan doesn't tend to use high quality orings in them and the ones that fail are the 2 inside the cap the shaft rides in since they're the ones that take the most abuse. Some also used to have a bleed screw on the rear cap for tinkering with the ram pressure, but it's been quite awhile since I bought a new Hatsan so no clue if they still do on some models or not.
Bit of a trick to replace but they can be and the ram refilled with a hand pump and Hatsan fill probe. I've got a list of the oring sizes for back cap, front cap and shaft seals.
Bit of a trick to replace but they can be and the ram refilled with a hand pump and Hatsan fill probe. I've got a list of the oring sizes for back cap, front cap and shaft seals.
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Ridiculously easy if you have a pump and the fittings if they are adjustable rams like Theobens.. Different models fill to different pressured...This SLR was filled to 50bar which yielded 16 ftlbs...An Elinimator..20 cal was around 80 bar which yielded 25flbs...Very low pressures compared to general PCP filling...Doesn't take much pumping at all...the rams have very low air volume. 
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The Hatsan Vortex is a high pressure ram. I fill the 95 to 125 bar (1800 psi) and the 135 to 150. (2175 psi)
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Bear, how often do your Hatsan Rams need pressurizing? Are they designed for this? I only ask because of the comments I read about "my Hatsan ram died."
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My HW 90 is fairly new but hasn't needed a change in pressure yet. Looking forward to acquiring an HW90 in 20 to compliment the 25 I have now. It just sounds like it should have the qualities I am looking for. Be Well B I O. Bandito.
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They are designed to let down and fill back. Easy to disassemble the gun by letting down the ram. I am told the new Vortex Rams do not let down. Not certain this is a fact. Mine all do.
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I've done it on my Hatsan, it was given to me dead. So I researched repairing it, and found that I could re-charge it. So I bought the proper fill probe, and did that. I woundup only getting a weekend of shooting out of each fill, so I cut the stock to accommodate the fill probe. It eventually wouldn't hold air at all, so its a wall hanger now.
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The Hatsan gas rams are no longer available with the bleed off screw. I do rebuild them with quality parts and lube. I also warranty the gas ram to hold pressure. I have a hatsan 135 in 25 caliber that was rebuilt about 5 years ago and it sill hold the same pressure as when I filled it. I know this because I have a way to test the pressure of the gas ram . This 135 is shot quite often and is stored in my safe with muzzle pointing upward.
I am not a Hatsan Hero (lol) just crazy or dumb enough to work on them?(maybe both)
I am not a Hatsan Hero (lol) just crazy or dumb enough to work on them?(maybe both)
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If you can provide the individual parts for this build it would help out the community big time, as they wouldn't need to buy the Brocock pump and accessories from over the pond!
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I know this, rebuilt many Theoben’s. Usually when this question gets asked most are referring to Crosman‘s and Gamo’s. Looking back at the question I see that it’s open ended.
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I bought this fill adaptor in 2010 from Jim at Precision Airguns. I want to say he had them made special by a hydrolic specialist company. The Hill pump end takes a double male nipple I think is 1/8 British pipe the ram end is a machined fitting with a shoulder to acceptj an oring...threads may be 5mm for a guess the entire thing would need swedged together with the hose...good luck with all that these days! If I wanted one today I would get the available one fron across the pond, I know of at least two guys who got theirs that way successfully.If you can provide the individual parts for this build it would help out the community big time, as they wouldn't need to buy the Brocock pump and accessories from over the pond!
View attachment 421597
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Before i modified the stock I had to remove it to charge this Hatsan for a weekend shoot.
It eventually developed a major leak. Perhaps it could be repaired someday.
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It can be, just takes pulling the ram out of the rifle, a bit of time and the right size orings. The cap that holds the piston shaft has 2 orings inside it and those wearing out is where the ram loses pressure and fails.
Not a great picture, but the orings inside that cap:
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