S400 Carbine Problems

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CitizenEra5ed
Posts: 8
Joined: Fri Aug 05, 2016 9:54 am

S400 Carbine Problems

Fri Aug 05, 2016 10:22 am

Good morning chaps, I've not been on AAOC for a long time (I was one of the orignal members when it was first started and still have my little AAOC badge you were selling in those days)

I've had to register with a new name as I think I was probably deleted a long time ago.

My S400 hasn't fired a pellet in about 7 years but Ive got it out today and found that it wont charge up. I remember ages ago hearing a loud bang (like a massive balloon popping) and had no idea what it was although I did suspect later that it might have been my air gun and it appears it was.

The gauge underneath the gun is indicating it has about 170bar in it but there is nothing. I connect the air bottle and open the valve and its indicating, straight away, just over 200 bar but it is putting nothing into the gun. The very first time i connected it and opened the valve, there was a noise like an internal air leak just for a couple of seconds and then nothing and its not done anything ever since.

Ive not had the gun apart yet but just wondering what I can expect to find and if its easy to fix.

The gun is like new and not even had 500 pellets through it but i'm looking to get started again with it.

Any help, tips, thoughts appreciated.

Chris

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CitizenEra5ed
Posts: 8
Joined: Fri Aug 05, 2016 9:54 am

Re: S400 Carbine Problems

Fri Aug 05, 2016 11:39 am

As an update, ive just been watching a few Air Arms videos on Youtube and saw the one where he replaces the gauge under the rifle.

I started to undo my gauge and air started to leak out. I let it empty and took the gauge fully off. I noticed the O ring was slightly nipped on one side but assume it must've been like that from new and don't have a replacement. I put a bit of light oil on the thread and O ring then refitted it and then refitted the stock.

I tried to charge up the rifle again, this time the gauge slowed increased from 0 and when it got to about 170, I shut the valve on the bottle. I noticed the pressure started to drop slowly and could hear a bit of a hissing.

I removed the stock again and found that air was escaping from one of the small holes next to the aluminium block that the pressure gauge is screwed in to. (the small section between where the trigger is and the main cylinder).

When the gun is first charged and before all the air leaks out, it still will not fire. You cock the gun, then pull the trigger and nothing happens.

Any ideas?

Regards

Chris

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

Re: S400 Carbine Problems

Fri Aug 05, 2016 1:25 pm

The block is called the dogleg. It is held in place by a hex head bolt that just needs nipping up. If that don't fix it then you will need a new o'ring.

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

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Raj
Posts: 2005
Joined: Sun Feb 15, 2015 9:36 pm
Location: Rugby

Re: S400 Carbine Problems

Fri Aug 05, 2016 4:59 pm

Before you try to fill your rifle, you need to cock it. Do that and fill again. Also, you may need a very short burst of air at the beginning to shut the valve ,... then your usual slow fill.
:)
“It's the Indian, not the arrow"

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TenMetrePeter
Posts: 1043
Joined: Wed Jun 29, 2016 5:40 pm
Location: Luton Beds UK

Re: S400 Carbine Problems

Fri Aug 05, 2016 6:02 pm

The Air Arms video on checking for leaks is basically dribbling sewing machine oil over every joint looking for bubbles.
I think you also need to check the sears under the trigger unit side plate and maybe even look at the hammer, hammer rail and firing pot. This is because nothing happens even with pressure up. If the hammer successfully whacks the firing pot then something is amiss in the area of the firing valve.

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CitizenEra5ed
Posts: 8
Joined: Fri Aug 05, 2016 9:54 am

Re: S400 Carbine Problems

Fri Aug 05, 2016 7:15 pm

Thanks for the replies chaps

Chris

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granville
Posts: 602
Joined: Sun Feb 15, 2015 7:33 pm

Re: S400 Carbine Problems

Thu Aug 11, 2016 9:26 pm

worth giving the hammer rail a clean and polish .

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