Maruader Pistol Pressure Gauge Leak

After tinkering about with my Marauder I had the very same leak. It was a clipped O-ring caused by sharp edges on the various openings in the main, air, tube. As I pushed the block down the tube and it passed the various openings in the main tube the O-rings were nicked just enough to make a slow leak. I deburred them and no more leaks. You might be able to wiggle it around and luck up and get a seal but if you have disassembled the gun I would suspect the same problem I had. You could always buy a bolt or plug with the same threads, pipe threads?, to eliminate the gauge as a leak point.

Edit: Its late and I just checked your post again. If the gauge wiggles in the block and the block is not moving the port that the gauge threads into is waaaay out of spec. and must be replaced. Basing this on how my Marauder is built. Is it under warranty? If not I would just get a new block or have it repaired by someone who knows what they are doing. 3K psi is not something to muck about with if you don't know what you are doing.

Had the same problem recently and it turned out to be the gauge block O-rings. Make sure to lube the rings when putting the block back in.

For any of you that might tinker alot with your marauders, a 1.25" 600grit(for mrods) .75" 600grit(for prods) ball hone will clean up all those edges and make the chances of cutting orings much less.

Same problem on my Marauder. Did a reseal and found the manometer gauge was still hissing. Purchased a McAlister 4000 psi mini gauge. The standard 1/2 " Teflon tape roll kept trying to roll off the end of the pipe threads of the pressure gauge when wrapping. I found that if you cut the Teflon tape in half, 1/4 inch strips at about 6 " in length I was able to really wrap the threads of the pressure gauge better for the seal. 

I am reviving this thread as I just ran into the same problem as member comovez. Took my prod out to hunt doves and the pellet came out so slow it bounced off the bird. I checked the gauge which earlier showed 2800 psi. Two hours later, it's at 800psi. 

I pumped it up and heard slight hissing from the gauge port area at the stem of the mamometer. The gun was emptied of air and I noticed the air gauge now moves left to right. Is that normal for it to move when there is no air pressure in the air tube?

Next, I change the o-rings on the gauge block and apply 100% silicone lubricant by Alchemy airguns on the block and rings. I slide it back in and fit the air gauge stem into the port hole and seal screwed it back in tight with teflon tape. I pumped it up and it held air at 2000 psi for about 10 minutes and then when I test fired it, there was a strong hissing sound and the gun just steadily emptied.

I filled it up and put soapy water around where the air gauge stem enters the port hole...i didn't see any sputtering bubbles.

Could it be the air gauge that is bad? Can air leak out of the air gauge?

I'm at a loss at this time.

Yes, air can leak out of the gauge.

Do you know if it's normal for the air pressure gauge assembly to move slightly left to right when the air chamber is completely depressurized?

Yes, that is normal when it is depressurized. The gauge block rides on orings inside the airtube, so there is play when no air is in the tube. Under pressure, it won't move.

Ajshoots, thank you for your information. I ordered an air gauge from talontunes; it seemed rugged. Hopefully this will work out. Thank you all again. If it doesn't work, I'll be posting a used marauder pistol for super cheap..LOL.

If you have any further issues, before you give up, pm me. I would be glad to help you over the phone fix, diagnose, or whatever you need. Let me know.

"ajshoots"For any of you that might tinker alot with your marauders, a 1.25" 600grit(for mrods) .75" 600grit(for prods) ball hone will clean up all those edges and make the chances of cutting orings much less.

Thanks a bunch AJ I will give that a try. Clipped orings seem to be fairly common.

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I saw the .75 "600 grit ball hone. Do you actually run that brush down the air tube chamber or just the air gauge port hole?

Down the airtube to hone away the rough edges of the holes and slots that were not deburred from the manufacturer. It will reduce cut orings when reassembling and also helps with consistent hammer strikes since you are now giving the hammer a really smooth consistent surface to ride on.