How to Replace / Renew GBB Mag Seals?

Here's hoping someone can help please, I've a GBB Beretta M93R that has a persistent leaking magazine seal(s)

Sending it to an Airsoft retailer sets me back £25 a time with everything and it's getting expensive

So, how are both Inlet and Outlet valves removed and how are seals replaced please

Can't say for M93R, but overall process is usually similar.

Check out "Auto9 parts" picture - this model is based on M93R, so the magazine is the same:
http://www.arniesairsoft.co.uk/?filnavn=/reviews/m93r/m93r_technical.htm

edit - updated URL:
http://www.arniesairsoft.co.uk/reviews/m93r/m93r_technical.htm

Bottom seems to be held by two pins. Parts 114/115 are bottom seals.
Part 136 is mag seal, not interesting for leaks. Valve is 108, it has to be screwed out using special valve removel tool (or maybe pliers if you are brave ;-) ) There should be additional seals sitting on the valve itself.

There are typically four seals: two in the bottom, two in the top valve. A fifth seal is a rubber piece that ensures proper transfer of gas between mag and blowback chamber, but it does not cause mag to leak.

To remove bottom valve:
- make sure there is no gas in the magazine
- remove bottom plate (just a cover, part 103)
- push out two pins that hold the bottom, (or unscrew a screw in other types of mags)
- pull out the whole bottom (#112 and other pieces), take care that spring does not spring out

Bottom will usually have a single square seal that goes around it. This seal is quite large, and often this is the one that leaks. M93R seems to have several seal made of several pieces - it's easier to fix I guess. The second seal is a very small o-ring that sits inside fill valve (perhaps between #107/#115), usually it does not need to be worked on. You would need to unscrew the fill valve from mag base to fix it.

Removing top valve is perhaps more complicated, as it varies much more among manufacturers. Often it has to be screwed out using valve removal tool. There could be two seals: one is an oring that sits between mag side and whole valve (near valve button on the inside), the second (o-ring or custom made) is directly on valve.

Fixing the seals can be done in many ways. The simplest one is to soak them in silicon oil for a longer time (12-24 hours). This should restore thickness and flexibility of the seals/o-rings and make them work again. If that does not work, silicon tape (plumbers use it) could be used for additional sealing, but it is very tricky to place properly.

To find source(s) of leak - put mag full of gas under water, observe where the bubbles form. This will for sure tell you if it's top/bottom, but might not be good enough to tell which side of the bottom.

Thanks very much smootik, this will be a great help

Arnies may be having some server problems ( ) as I couldn't access http://www.arniesairsoft.co.uk/reviews/m93r/technical_images/auto9_parts.gif
and
http://www.arniesairsoft.co.uk/reviews/m93r/technical_images/93c.jpg

but the last link you kindly quoted opened up without a problem. My 93R is a MGC/Taito version but I'd imagine there won't be much difference at all taking the mag apart.

If dried out seals can be restored by soaking in silicone oil, are new 0-rings easily available if I find some cracked or split
I assume a universal valve removal tool can be bought from any on-line Airsoft dealer

Many thanks for your help and instructions again,

Arniesairsoft seems to have a requirement that you need to visit main review page first and then click on image link.
I cannot open images directly from here either.

Tool for valves should be pretty standard, see example here:
http://shop.ehobbyasia.com/guarder-valve-key-for-wa-ksc-gbb-magazine.html

Spare parts might be available. I've checked KWA USA (related to KSC), but they don't have the bottom seal, only fill valve and top valve seals:
http://store.kwausa.com/kwam93riipartslist.aspx
http://store.kwausa.com/m9series.aspx

UK shops might still carry appropriate part, but UK guys would need to comment on that.

Thanks very much again smootik.

all the info you've given here is very helpful