Reply With QuoteCould also be dirt in the pressure relief valve in the pump head, or its opening too early. This is the spring, ball and seal that keep the power of the rifle below the 12ft lb UK level.
Baz
Registered User
I received new o-rings and the two springs that go either side of the exhausts valve from Chambers. I also got a new pump handle as the one that was fitted was suprisngly incorrect- it was more bulbous and had a small rubber bumper part on the end.
I fitted all the parts and was able to pump it 4 times and it all appeared to be working. It fired normally once but on the next go it appears that it doesnt build up pressure. Basically it just pops a little bit of air regardless of the number of pumps.
I pulled it all apart and l'm convinced that the ball bearing has a small rough spot and l'm sure that the seal that the ball seats on is not pristine.
Would these two parts cause the above symptoms? Anyhow l ordered a rebuild kit from TR Robb as Chambers did not have all the bits the first time.
George
Registered User
Could also be dirt in the pressure relief valve in the pump head, or its opening too early. This is the spring, ball and seal that keep the power of the rifle below the 12ft lb UK level.
Baz
BE AN INDEPENDENT THINKER, DON'T FOLLOW THE CROWD
Mushroom Man
Strikes me that we could do with a Strip Down and Rebuild Guide over in Collectables, Idiots Guide.
Any takers?
Cheers, Phil
Registered User
Did all Innovas have the pressure relief valve (keeping in mind that l'm in Australia).Originally Posted by Benelli B76
Looking at mine, the seal doesn't have a hole in it and the brass bit is quite short.
George
Likes a bit of Pumping
I wrote it years ago PhilStrikes me that we could do with a Strip Down and Rebuild Guide over in Collectables, Idiots Guide.
Any takers?
Cheers, Phil
Matty
Opportunity is missed by most people, because it is dressed in overalls and looks like work.
Likes a bit of Pumping
Hi George
NBS007 is a Nitrile British Standard size 007
It's really important that you use an o ring this size for the exhaust valve as if it's too big it will leak and if it's too small the valve stem will not pass back through fully after you fire the gun.
Your current symptom sounds to me like an O ring the wrong size (too small a hole) on the exhaust valve.
Matty
Opportunity is missed by most people, because it is dressed in overalls and looks like work.
Registered User
Hi Matty,
Thanks for the info, l assumed that all the seals would be metric.
Luckily l have a kit with that exact size o-ring so l'll give it a go.
Cheers
George
Registered User
Sorry George, forgot you were in Oz, and have full power rifle. Adelaide is one of my favourite towns, very similar houses and wide roads as where I lived in Port Elizabeth South Africa. Used to land at Adelaide to visit my daughter in Berri. Now go to Bairnesdale where she moved to, do a bit of Sambar hunting there.
Baz
BE AN INDEPENDENT THINKER, DON'T FOLLOW THE CROWD
Registered User
No problems Baz. I went the other way, grew up in Melbourne and moved to Adelaide. With a bit of luck, l'll be sambar hunting near Bairnsdale in a couple of months-that region of Victoria is sensational if your into hunting and fishing. Hopefully one day l'll get to see South Africa.
Cheers
George
Registered User
I still haven't received my refurbishment kit from TR Robb yet but l couldn't wait.
I installed a BS 007 o-ring on the exhaust valve (thanks Matty) and I managed to find the correct ball bearing (9/32").
I put a few pumps into it and I could feel the pump handle getting harder so I knew it was working. I discharged this and tried again but it would not build pressure. I couldn't hear any obvious leaks but I could hear the exhaust valve or the ball bearing moving-hopefully this is normal.
l then held down the trigger and tried to pump it and it was clear that air was now leaking out the chamber. I then tried re-pumping it up and it appeared to be working. I went through this cycle a few times where it would work a few times and then it wouldn't. But it now seems to have settled down and all is good. I stopped after about a dozen shots without any issue.
I put a few shots through the chrony and although I didn't write the numbers down all appears well- the velocity was in the high 600 f/s. Obviously I will have another chrony session soon and I'll check the power levels. I still need to change the bolt o-rings as well.
I can now start to deal with the stock and sort out the sights. I'm still hoping to track down a front sight and even a rear sight ,so please let me know if anyone has one that they want to sell.
Thanks for everyone's help so far, I have had a heap of fun playing with it.
George
Registered User
Hi All,
My full rebuild kit has finally arrived from TR Robb.
Even though l have managed to get it to work with the various seals that l cobbled together, l now wish to rebuild it properly for the final time. I got it to work but occasionally the exhaust valve sticks open and doesnt hold pressure. I'm convinced it is the valve itself so that why l bought the TR Robb kit as he was the only place that had these in stock.
Anyway, the kit comes with a dab of white coloured grease and a small bottle of oil. What is the correct lubrication that l should use to rebuild the Sharp. I'm assuming the grease is for smearing on the o-rings and the oil is for the the pump arm linkages etc. Previously l used Dow Corning silicone grease on the o-rings.
Also, l'm still desperately looking for a front sight assembly. Yes l missed the one in the classifieds.....
Regards
George
Registered User
Be careful which silicone grease you use on ' O ' rings as some are designed to swell o rings for a perfect seal but these are no good if the o ring needs to move/slide in use.
Check on the Dow Corning website for the one to use, I think it's molycote 33 ? Not sure though.
Registered User
Thanks, l never considered that.
I checked and the grease supplied in the TR Robb kit is Molykote 33.
Hopefully l'll get a chance to play with it on the weekend.
George
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