S410 leaking pressure gauge

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RickDastardly
Posts: 7
Joined: Mon Jul 10, 2017 2:21 pm

S410 leaking pressure gauge

Mon Jul 10, 2017 2:35 pm

I hadn't used my S410 for a few years (due to illness) and when I tried it out the other day, it quickly lost pressure. I tracked it down to a leak under the pressure gauge; I could hear it and that's where the oil bubbled.

So, I replaced the pressure gauge seal (which felt like hard plastic), and the seals on the mounting block for good measure. On reassembly, I found the pressure gauge itself leaked, out of the hole in the side of it. I don't know if it was also leaking there at the start.

Is it likely that I damaged the gauge by removing it with adjustable spanners? I didn't slip or anything silly and it's hardly he first thing I've taken apart. The rifle hasn't been dropped or anything and was well cared for before it was packed away.

More importantly, before I buy a new gauge (I'm *really* short of cash) is there likely to be anything else that might have caused this failure? What I mean is, is there anything else that could have caused the pressure gauge fault, that I'll only find after replacing that?

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Blackbaronfish
Posts: 3690
Joined: Sun Feb 15, 2015 6:20 pm
Location: Nuneaton

Re: S410 leaking pressure gauge

Mon Jul 10, 2017 6:01 pm

You may have screwed it in a bit too tight.
Try backing it off a bit. Also make sure it's the right o'ring

BBF
Did I mention that I'm the only one to have attended EVERY meet since we started

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RickDastardly
Posts: 7
Joined: Mon Jul 10, 2017 2:21 pm

Re: S410 leaking pressure gauge

Mon Jul 10, 2017 7:26 pm

Thanks for your reply.

I just tried loosening it a little, then a bit more. Just short of the point that I thought I might loose the seal completely. It made no difference. I didn't have it that tight to begin with and actually tightened it a little more when I realised there was still a leak, before I found it was now coming from the hole. I did read about the possible issue of over-tightening the gauge.

The air is coming out of the hole in the side of the pressure gauge; quickly enough to make an audible hiss and instantly blow away a drop of oil. It is not coming from the sides of the seals any more.

I'm pretty sure I used the right o-ring. I bought a pack of seals which came with a printed sheet showing the sizes. It was reasonably clear which one matched, once I put my glasses on.

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TenMetrePeter
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Joined: Wed Jun 29, 2016 5:40 pm
Location: Luton Beds UK

Re: S410 leaking pressure gauge

Mon Jul 10, 2017 7:51 pm

22mm box spanner is cheap to buy on ebay.
Like Bbf says its a rubber o-ring not hard plastic.
New gauge is about £25ish if its leaking out the casing hole. Probably a split bourdon tube.
Ask Julian in Spares section by PM for a price. Comes with the o-ring usually.

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Roger5
Posts: 1071
Joined: Sat Jul 25, 2015 8:04 am
Location: Hampton middlesex

Re: S410 leaking pressure gauge

Mon Jul 10, 2017 7:58 pm

The o-ring under the manometer is RN219-9 Rog

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RickDastardly
Posts: 7
Joined: Mon Jul 10, 2017 2:21 pm

Re: S410 leaking pressure gauge

Mon Jul 10, 2017 8:11 pm

Thanks folks. To clarify, I meant that the old o-ring that I took out was like plastic, not the new one.

I'll send Julian a PM. Thanks :)

I'll also pull the rifle apart and use the rest of the seal kit, and give things a spit and polish. Might as well.

I was only checking it out because I was thinking of selling up :cry: and needed the money. It was fine when I last used it. Good thing I noticed the pressure drop. Can't sell it with duff seals.

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Blackbaronfish
Posts: 3690
Joined: Sun Feb 15, 2015 6:20 pm
Location: Nuneaton

Re: S410 leaking pressure gauge

Mon Jul 10, 2017 9:34 pm

Put a new one on then, you tight dastered :lol: :lol: :lol:

BBF
Did I mention that I'm the only one to have attended EVERY meet since we started

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RickDastardly
Posts: 7
Joined: Mon Jul 10, 2017 2:21 pm

Re: S410 leaking pressure gauge

Mon Jul 10, 2017 9:51 pm

:lol: :lol: :lol:

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peterlnic
Posts: 18
Joined: Sun Jun 04, 2017 3:21 pm
Location: Skelmersdale, Lancashire.

Re: S410 leaking pressure gauge

Wed Aug 02, 2017 2:14 pm

Hi there,
i know what it's like to be short of cash, i'm disabled and unable to work, so cash is always tight, i have known pressure gauges to 'blow' and leak out of the little hole, do you still need an original AA-S400 gauge? i can't promise but i may still have one, i spun up an adaptor to take a PSI gauge in stead of a BAR gauge as i fitted a new stock which was deeper so needed an extension to bring the gauge flush with the stock, anyway, enough of the incoherent dribble, i may still have the original AA gauge, drop me a PM and i'll go and look if i still have it.
Good Health to you all, Pete.
Heavily Modified 'AA S400' Konus 12-60x56 scope,
'Dayststae Mk3' 10-40x50 scope,
Home made PCP 8-32x44 scope,
AA 'TM-100' (now restored and shooting well),
AA 'FTP900' 10-40x56 Nikko-Diamond scope,
'Rohm Pistol' Reflex sight.

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