Seals and lubrication for FAS 604

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micken
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Seals and lubrication for FAS 604

Post by micken » Sun Jun 23, 2013 9:08 am

I recently acquired a FAS 604 that I'm intending to use in the MPL. When it arrived it shot OK but within 300 pellets or so the seal at the top of the valve assembly started to leak. On stripping it down I found that all of the seals were the red silicone ones. I've replaced them, using the slightest smear of Molykote 101 to condition the seals, but the valve head seal leaks after a couple of hundred pellets. I'm going to use a nitrile seal with a higher Shore value the next time round and if that doesn't work I'm going to gently work on the valve seat faces to remove any burrs.

Having researched lubrication for ssp pistols I've come across detergent free oils, atf fluid and various brake fluids as well as commercial products at premium prices.

So my questions are:

What types of o-rings are others using in the FAS 604?
Could anyone please recommend an appropriate lubricant for the piston and valve system in the pistol?

Thanks,

Mick

Adam77K
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Re: Seals and lubrication for FAS 604

Post by Adam77K » Sun Jun 23, 2013 12:13 pm

I don't think there's anything better for SSPs than the classic pellgunoil, or equivalent like M9D oil.

micken
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Re: Seals and lubrication for FAS 604

Post by micken » Sun Jun 23, 2013 3:39 pm

Thanks for your reply Adam, I may well try either of those.

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Appinpar68
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Re: Seals and lubrication for FAS 604

Post by Appinpar68 » Sun Jun 23, 2013 3:53 pm

I replaced the seals on my FAS 604 with these seals available for £6.40 on Ebay
with a little bit of moly paste shoots as good as new

http://www.ebay.co.uk/sch/i.html?_trksi ... &_from=R40" onclick="window.open(this.href);return false;


Graeme

micken
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Re: Seals and lubrication for FAS 604

Post by micken » Sun Jun 23, 2013 8:01 pm

Hi Graeme, thanks for the link. Yes, those o-rings are the silicone ones. I used moly paste very sparingly in my Gamo Compact and I'm inclined to try that. I think some careful attention with wet and dry paper might be needed.

Cheers,

Mick

RobinC

Re: Seals and lubrication for FAS 604

Post by RobinC » Wed Jul 10, 2013 12:54 pm

Having had a FAS 604 new when they first came out in the early 80's, I used it for five years and then gave it away to my brother in law, and he still shoots with it to this day and makes his county team. I also bought a new one a couple of years ago, I am very surprised to constantly hear of people having to replace the valves and o rings. My first one went 30 years of regular use before the seals went, my current one has run for 4 years perfectly from day one and still is.
The current trend of people to believe that the pistol needs "servicing" even though its working perfectly has impacted adversly on FAS 604's. If it ain't broke don't mend it applies particularly to FAS 604's, and when you do need to, cheap o rings last months where as the original and factory replacement ones last many years. as for lubrication, they are best waved past a can of lubricant at build and then left for years than liberaly doused as many are.
The best man I know for FAS work who will only use and supply original parts is Bob Cleverly at Checkmate guns.
Have fun and good shooting.
Robin

micken
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Re: Seals and lubrication for FAS 604

Post by micken » Wed Jul 10, 2013 2:04 pm

Hi Robin and thanks for your input. I've replaced all the seals with nitrile ones and used a drop of pellgun oil too. These seals se
em to be more well suited to the job.

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