What is an acceptable rate of pressure leak in a PCP?

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Bigragu

Bigragu

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Jul 8, 2018
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CA, United States
I sure would like to say all PCP’s never leak, so if that holds true, please advise. While sighting in my Wildcat and Bully yesterday, I decided upon pick up time since I had my tank out and set up I would top off my other two pcp’s, a Marauder rifle and a Marauder pistol. It’s been about almost a month and a half(maybe to months, can’t recall for sure) since I last topped off my unused guns, and the rifle still was at the regulated 2150 psi pressure. The PRod though, was at 2600 psi down from 3000. So, say it’s been two months, there’s a loss of 400 psi, so that comes out to around 7 psi/day rounded off. 

Anyone else with a PRod that leaks or has leaked? I’m trying to figure out where the most common place for a leak to happen on this pistol. I bought it brand new last August. When I had it apart the one thing I didn’t like where it differed from the Marauder rifle, is it had no gage O ring seal, but used Teflon tape instead. I’ve used a leak detection solution on the fill area and gage area and no bubbles. 
 
I guess what's an acceptable leak is up to you. Depends on how much time and money you want to spend to find said leaks and fix them. 7 psi per day isn't bad, but if you are OCD like me, it'd drive you nuts till you find a solution. Otherwise, if you aren't that OCD, this might be like that slow oil leak in the car, you know, a quart every 5000 miles. Just feed the habit till it's time to do a rebuild and then, seal it up tight. Just a thought.
 
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Pcp's should hold air indefinitely, they're design is intended to do so, but flaws/imperfections are a part of our lives.



Very small leaks like that sometimes don't show themselves well without being entirely submersed in water, I would remove all parts that aren't necessary to retain HPA (trigger group, hand guard, hammer, tp, barrel, and then dunk the HPA tube into water and wait for a bubble, could take minutes or seconds. Once discovered dry everything off very well and tend to the problem area! Good luck.



-Matt


 
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Pcp's should hold air indefinitely, they're design is intended to do so, but flaws/imperfections are a part of our lives.



Very small leaks like that sometimes don't show themselves well without being entirely submersed in water, I would remove all parts that aren't necessary to retain HPA (trigger group, hand guard, hammer, tp, barrel, and then dunk the HPA tube into water and wait for a bubble, could take minutes or seconds. Once discovered dry everything off very well and tend to the problem area! Good luck.



-Matt

Click to expand...

Gas fitters leak detection spray is a less drastic method, get the aerosol type with a tube nozzle for precise application. I use a complete submersion in water is the last resort.

Bb


 
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I sure would like to say all PCP’s never leak, so if that holds true, please advise. While sighting in my Wildcat and Bully yesterday, I decided upon pick up time since I had my tank out and set up I would top off my other two pcp’s, a Marauder rifle and a Marauder pistol. It’s been about almost a month and a half(maybe to months, can’t recall for sure) since I last topped off my unused guns, and the rifle still was at the regulated 2150 psi pressure. The PRod though, was at 2600 psi down from 3000. So, say it’s been two months, there’s a loss of 400 psi, so that comes out to around 7 psi/day rounded off. 

Anyone else with a PRod that leaks or has leaked? I’m trying to figure out where the most common place for a leak to happen on this pistol. I bought it brand new last August. When I had it apart the one thing I didn’t like where it differed from the Marauder rifle, is it had no gage O ring seal, but used Teflon tape instead. I’ve used a leak detection solution on the fill area and gage area and no bubbles.
Click to expand...

Check that no air is escaping through the firing valve out through the barrel.
 
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Pcp should not leak. I have store pcp guns 3000 psi for months without shooting and it's still at 3000 psi. If you have a small leak. Check filling nipple. Gauge hole, and at the valve ports. Use soapy water or leak detector. If can't find due to very small leak. Remove everything but the air tube and dump in a tube on water. You will see bubbles if it is leaking.
 
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It's mechanical system. Anything can have defects. How much would certainly seem to be difficult to quantify from gun to gun. I have a pp700 that's been in my storage drawer for at least 3 months and has moved maybe half a needle. I also have a couple of SPA rifles and a Condor that will each drop 10 to 15 bar a week. They still shoot great so I'm not going to mess with them for that. Others may have to work on such a level of drop to be satisfied. Seems, like many other things, to be relative.
 
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I got a refurb Disco from Normand at DiscoSRus, along with a couple of Marauders. The luck I had with his refurbs was way better than any brand new Crosman product friends or I received. That Disco was still holding after three years of non use. For myself I was resealing a Cricket, after two tries I was still getting an occasional bubble when the tube was stored in a tall glass of water. Was it the pressure eventually set the seals or what that gun holds forever now.
 
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The acceptable rate of leakage is zero. I have several PCPs which have been sitting in the box for two years without any drop in psi. My Huben K1 recently exhibited leakage at a rate of about 30 psi per day ( 4 times faster than yours ). The use of soapy water quickly identified the location of leakage which is fixed by lapping the seat of the O-ring .





https://www.youtube.com/watch?v=76XD9IHQjOU 




 
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I'd start by leaving a balloon over the end of the barrel for the night?

1557275952_21059026385cd22530900c29.68510764_thomasleak.jpg


Fuss
 
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