It's been too hot here to shoot much but I did shoot a little recently to check zero on some of my pesting guns. I shot the pp700 down to around 120 bars and intended to top it back up but forgot to do so. A couple of days later it was empty. Filled, it holds pressure fine long term. The only thing I can think is that the hammer spring might have put enough pressure on the valve at the lower reservoir pressure to slowly bleed off the air without it being heard. Anyone else noted something similar with a PCP or have other ideas?
Interesting pp700 occurence
- Thread starter bandg
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Get your PP700 to the 120bar, make up a dish soap solution get a little on your finger anf cover the 2 fill probe holes see if bubble developes, another option place a small ballon over the fill hole area tape to tank if needed. see if it fill s up. I have a a few of these do the same thing at lower pressures, end result was oring on check valve screw stem, It is really just a o-ring around a screw not a true check valve.
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Most of us have found great tunes using fairly low hammer spring preload ... set as such this becomes a non issue.
* but YES, is HST is cranked up there becomes a LOT of preload on the poppet
* but YES, is HST is cranked up there becomes a LOT of preload on the poppet
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If you want to verify for sure what you suspect just fill to 120 bar then either wrap a rubber band on the hammer and beaver tail to allow a tiny gap between the hammer and valve pin. Or put something like a car tire valve stem cover or male foster dust cover over the pin then lower the hammer so it doesn't touch. Wait to see if it still leaks like before.
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This is what I was looking for-experience with the same type thing and a possible mechanism. Thanks.
Motorhead
I have a very stable accurate high velocity tune now and don't want to try to reset for a lower HST. It isn't really a functional issue as it doesn't leak at normal ready to shoot pressure and is always stable for use when picked up if filled fully. I was looking for other experiences with low pressure leaks and what might cause them. But thanks.
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I've adjusted mine while filled but it's been a very long time since I did any adjustments to the reg. I don't recall any specific advice but IN GENERAL I think it's probably good to degas before adjusting most guns. The pp700 is such a small air volume, filling it isn't hard even with a hand pump so degassing isn't a big issue.
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G
Guest
Guest
For me it was the fill check valve oring getting chewed up by unfinished surfaces. I smoothed them out and bought tougher orings. Problem solved.
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