Benjamin Marauder - Huma Leak

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Bramezy

Bramezy

Member
Jan 1, 2018
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Hamilton, Ohio, United States
Alright searched first without resolve.
Gen2 marauder. Putting in a huma reg with gauge port. Air leaks at the fitting of the extension going into the huma reg itself. Will this not seal? Ive used the stock oring and a white bspp seal and nothing seals. Ive tried all different combinations of gauges and seals.
Not sure its the gauge. I’ve replaced the orings on the reg twice and on the valve. Tried being super careful with lube and pushing the orings down n past the opening. Taking cautions not to damage them.
Could it be the reg itself? Seems like it has to be the huma reg body orings but im not positive.

IMG_9939.jpeg
 
Stubbers said:
It could also be o-rings on the regulator body itself, very likely cause as they nick easily when passing that hole.

-Matt
Click to expand...
I've got a american tactical liberty nova 22 and it has a funny air leak I haven't been able to find..
so I fill to 4200 psi and then in a week it's 3000 psi and second week it is 2000 psi and I think that's the regulator pressure.. after that it doesn't leak.. just curious I left it there a month and it's still 2000+/- psi..
I'd think normally if you have a leak just about anywhere it would go all the way down..
had a regulator for painting in the shop that developed a leak and it would drain air pressure down to the set point.. so I'm wondering if there's a atmosphere port on air gun regulator and possibly that is where it is??
please any information will be appreciated
thank you
Mark
 
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Bramezy, that's a tough spot to diagnose. I think I would see if I could remove the guage extension and install a pipe plug( if you can find one with matching threads). This way you can carefully apply soapy water with a syringe on your targeted areas. I agree with Stubbers that you could have nicked or rolled the regulator body to air tube seal that is most rearward(if you installed the regulator from the fill end). Its easy to do, especially if you hadn't lightly de-durred the guage hole in the tube.
 
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It's also possible that the leak could be from the internal o-ring in the regulator that seals the regulator body to the plenum itself. Those rarely get damaged by us, as it is internal, but if it is not sealing right the air will leak past it and out the gauge port hole.

That's the tricky part about air coming out that hole - it could be from five different places, even though it all flows out there. It could be the gauge port seal, the front and rear seals to the tube, the internal seal to the plenum, and lastly from a failed regulator out the atmospheric vent hole. Good luck!
 
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Bramezy said:
I tore the reg apart and found a hard and cracked oring.
Click to expand...
A common failure mode. If you don't plan to shoot in extreme cold conditions, consider using Viton (FKM) on the small end of the piston and the brass adjuster for better resistance to the heat stress of the refill cycle. For the typical Huma in-tube reg, the size of both is M1.5 x 5.5

Examples:

1.5mm X 5.5mm V75 Fluorocarbon FKM O-Rings 75/80 Durometer Black (JIS S6-V75) [V1.50X005.5] : The O-Ring Store LLC, We make getting O-Rings easy!

The O-Ring Store LLC 1.5mm X 5.5mm V75 Fluorocarbon FKM O-Rings 75/80 Durometer Black (JIS S6-V75) [V1.50X005.5] - Cross Section "CS" X Inside Diameter "ID" Chemical Resistant Fluorocarbon FKM O-Rings 75/80 Durometer: Chemical Resistant Fluorocarbon FKM O-Rings:, has excellent resistance to high...
www.theoringstore.com
 
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3Crows said:
Did you install the face O-ring on the aft end of the Houma plenum that makes the seal between the plenum and the gauge block? (and my first post here possibly, not sure).
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Yes but there is no gauge block, there are two orings on the outside of the reg. I tore the reg down and found a hard cracked oring inside. Hoping thats it. Ordered a rebuild kit from Huma 3 days ago but no contact from them over multiple emails. Be nice of a US source for these.
 
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Bramezy said:
Yes but there is no gauge block, there are two orings on the outside of the reg. I tore the reg down and found a hard cracked oring inside. Hoping thats it. Ordered a rebuild kit from Huma 3 days ago but no contact from them over multiple emails. Be nice of a US source for these.
Click to expand...

Fingers crossed for ya, I have faith you are on the right track. If you know the o-ring dimensions, you could order from this ebay shop, he sells in sets of 4-5 commonly at a very reasonable price (3.50 shipped).

Security Measure

www.ebay.com www.ebay.com
 
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Stubbers said:
Fingers crossed for ya, I have faith you are on the right track. If you know the o-ring dimensions, you could order from this ebay shop, he sells in sets of 4-5 commonly at a very reasonable price (3.50 shipped).

Security Measure

www.ebay.com www.ebay.com
Click to expand...
have tried measuring with calipers. hard to tell as they are flattened and hardened. I tried 4 different for the exterior before I ordered a marauder seal kit. Ill have to stop wasting money on them and be patient for once. Hope Huma delivers
 
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That is what a regulator does. Before the regulator you had the full pressure of as much as 3000 psi and the full reservoir as well as a giant plenum. Now you have regulated pressure much less than 3000 psi and you have only the plenum area behind the regulator. So, to make up for that you may need to open up the TP and barrel port.
 
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Bramezy said:
Rebuilt the reg and that was the issue. Now is tuning. I cant seem to get a 10.5gr above 880 when unregulated it would shoot over 1,000. Ive played with diff reg settings and that seems to be the fastest i can get with 1,500psi and less.
Ill keep researching but ideas?
Its stupid consistent, only about 38 shots on reg.
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Having been custom tuning M-rods for over 10 years now ... here is a copy and paste from another thread on another AG forum. I Quote:

Having a .177 M-rod myself ... Regulated & modified to take max advantage of it, Then doing the same conversion now likely 25+ times for customers I've got a very good handle on it IMO.

Regulated, Light hammer, different spring rate on poppet & some minor valve mods ..... SHOOTING 10.3 Grain for Field target work at @ 900 FPS being about 18.5 FPE .... 80 to 95 shots in all instances !!!
Take power down to a 800fps with an 8.4 your at 12 fpe and while a lot lower output, the factory port sizes are now honestly too large and getting a stable & efficient tune is not proportional being @ 130 or so IIRC.

Scott S

PS,
This with a STANDARD M-rod and NOT an F&T version
;)
 
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Motorhead said:
Having been custom tuning M-rods for over 10 years now ... here is a copy and paste from another thread on another AG forum. I Quote:

Having a .177 M-rod myself ... Regulated & modified to take max advantage of it, Then doing the same conversion now likely 25+ times for customers I've got a very good handle on it IMO.

Regulated, Light hammer, different spring rate on poppet & some minor valve mods ..... SHOOTING 10.3 Grain for Field target work at @ 900 FPS being about 18.5 FPE .... 80 to 95 shots in all instances !!!
Take power down to a 800fps with an 8.4 your at 12 fpe and while a lot lower output, the factory port sizes are now honestly too large and getting a stable & efficient tune is not proportional being @ 130 or so IIRC.

Scott S

PS,
This with a STANDARD M-rod and NOT an F&T version
;)
Click to expand...
Ive been reading up and seeing just what you said needs to happen. Do you have a recommendation on parts used? JSAR or Hill? Looking at the hill setup and its quite pricy to get his entire kit. I have not found what to do on the valve as far as mods aside of buying a new one built for this. The hammer and springs seem fairly straight forward.
 
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Stubbers said:
Hmm what are the stock ports like on the .177?

One option may be just slapping in a stock .25 cal valve from crosman as those come with .14 ports and you can match it with a .25 transfer port if needed and then all you would have to do it port the barrel. That's if the .177 valve is different as I'm unsure.

-Matt
Click to expand...

The only difference between the .25 valve and the .177/.22 valve is that the .25 valve gets a different poppet spring.
 
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3Crows said:
The only difference between the .25 valve and the .177/.22 valve is that the .25 valve gets a different poppet spring.
Click to expand...

Gotcha he must have the huma reg with a tiny plenum then. He could just get the larger plenum body or bump pressure up instead of opening the ports...seems less expensive. I bet huma may sell the larger plenum body alone.

-Matt
 
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