Leaky mag repair?

Mr. Tezza

Hey guys and gals,

Was going through my mags for my pistols today (2x USP .45 full size) and the mags are leaking fairly bady, is there anyway I can repair them and/or how would this be done, is it just an issue with perished seals or whats wrong with them?

Thanks in advance

Joe

tudenham10

Depends on where they're leaking from, if they've been lying up for a while, the valve towards the top of the mag might need a tighten (valve key the best for the job) and likewise the fill valve at the base.

Other than that, if you discharge all gas, place a few drops of silicone oil into the gas router, seal the mag in an airtight plastic bag and soak in very hot water for 10/15 mins and see if that solves it. If not, then I would imagine its needing an o ring replacement.

The_Joker

Another method to expand the rubber seals is use some fully synthetic oil, it's designed for seal swell and won't erode silicone rubber.

Mr. Tezza

Well one of them when you fill it just expells all its gas out the top, the other 3 seem to have a slower leak, you can just hear a hissing noise from them when you can has into them... haven't gone at them yet, think I have a valve key, not sure...

Inari

One of the best things you can do is just carry out some maintenance on your magazines.

Remove the plastic base-plate from the magazine, and then tap out the two pins found in the track. This frees the two pieces of the magazine housing from each other.

From here just inspect the O-rings on the inner piece. Do they look dry, worn or receded? Personally, what I do is take off the O-rings, put 1-2 wrappings of PTFE tape underneath. I lube up the O-ring, and replace it.

For the fill valve I simply remove, disassemble and inspect again, lube up and reassemble.

For the main valve I remove, look at the O-rings, and look at the spring. Sometimes the springs weaken and keep the valve open. This typically happens from the colder gasses *cough* Co2 *cough*, but it pays to be thorough.

I then reassemble the whole thing and test. I know it sounds a little redundant, but it just means you know exactly what's going on inside the magazine. You might not fix the problem, but it makes you more aware of what it is not, at the very least.

Mr. Tezza

Thanks for the helpful advice Inari I must take a good look at them when I get a chance, after the Rep. of Ireland vs Croatia game!!!

OzCam

I had two leaky mags which were fixed by replacing the O rings. You can sometimes buy a set in Aldi/Lidl very cheaply.

I tried the PTFE tape fix first. Sometimes it works, and if it does, great. If not you'll need to replace the seals. Don't forget a bit of silicone grease when you're reassembling everything.

It's not as hard as it looks. Just take your time. And don't lose the pins.


PS: A tip that worked for me when disassembling something for the first time or without instructions is to use a phone or camera to take photos at each step. You can then use the photos in reverse order to help with the reassembly.

Inari

OzCam wrote: »

I tried the PTFE tape fix first. Sometimes it works, and if it does, great. If not you'll need to replace the seals. Don't forget a bit of silicone grease when you're reassembling everything.

This.

It is not a fix-all solution. It is just a fix most. Sometimes you just need new O-rings. Most of the time you get away with engorging or buffing out, but sometimes it's a case of replacing them.

For the magazine that's leaking out of the top, tighten the valve with a valve key and re-examine. If leaking slightly, and tightened all of the way, use a needle-nose pliers to gently pull the main part of the valve out and see if that stops it. It's only gentle; don't force it. If that seals the mag then the valve's spring is too weak. Just heat it and stretch it