Glock 17 (Army Armament R17, TM-compatible) magazine broken output valve - FIXED

[martin2112]

After having problems taking out the mag from the pistol, I inspected it (mag) to find the button (A) detached/unglued/undone from part B. See attached image.

I thought at first they were threaded, but they seem to be tight-fit. There is a small groove on A, but I can't imagine how it would catch onto B's interior, as that is very slick inside. Maybe I'm missing a small but critical part that might have been ejected when I pulled out the mag?

I have never seen these valves in their working state. I'd appreciate any help on how A and B are supposed to hold, and possible solutions, aside from buying a new mag or valve. I do plan on buying an extra mag later, when the gun has proven its worth.

Thank you.

[Kos-Mos]

Just buy a new valve. It is supposed to be press-fitted/molded over.

Basically the black A part expands a lot less than the brass B part, so when full opened, the A part will fit and hold into the bottom part of B part, into a small groove that is not visible from the outside of the hole.

Having it back in one piece and have it work properly is a LOT more work than what the new part is worth.

[martin2112]

Originally Posted by Kos-Mos

It is supposed to be press-fitted/molded over.

Ok, that's the info I needed to attempt a fix - without making matters worse!

Originally Posted by Kos-Mos

Basically the black A part expands a lot less than the brass B part, so when full opened, the A part will fit and hold into the bottom part of B part, into a small groove that is not visible from the outside of the hole.

Interesting point about different expansion coefficients. I would think the manufacturers would account for the range of operating temperatures.

I don't quite understand the relationship between the valve being "full opened", and the fact that the parts should be as one (all the time, any valve position).

Originally Posted by Kos-Mos

Having it back in one piece and have it work properly is a LOT more work than what the new part is worth.

Well, I tried a very simple solution:
1) I cleaned the both metal parts with alcohol and dried them.
2) Wearing glasses (safety first!), I filled part B's cavity with 2-3 drops of Crazy Glue and reassembled the valve.
The glue actually took considerable volume and made part A stick out a bit too much. This caused a partial purge of the mag upon insertion into the grip. I had to hammer in part A - not lightly: medium force, as vertical as can be, to avoid bending the valve stem, B. Maybe less glue, and inserted a bit sooner would have helped. I do tend to take my time with Crazy Glue, to avoid having my fingers part of the assembly!

I had prepared a clamp, but did not use it since the bond felt already rock solid. I did not wait 30 minutes, but rather just the time needed to screw the valve back in, fill up, and let the mag warm up. Perhaps seven minutes. I was able to fire 32 shots. I'm happy.

I will update this thread if the solution fails.

I agree that buying a valve would be a sound solution, now that you confirm that it is broken. Thanks for the reply.

Finally, what's my best bet (retailer) considering we're in Canada. I don't want a bill like this:
TM Release/Outlet/Output? Valve: 7.00 USD
+ S&H: 28.00 USD!

[Kos-Mos]

Sorry, I assumed that you knew how industrial press-fitting worked.

They are usually heated around 200 degF before assembly. That makes the brass part expand a lot more than the steel part, thus making the fit snug or slightly lose. When going back to normal temperatures, the fit is very tight and usually will prevent the parts from going appart.

Crazy glue will not work. The glue is probably only dry on the surface of contact. The reason why you had a hard time fitting is because the liquid glue cannot be compressed since it is liquid. When it breaks again (it will, crazy glue is a cyano-acrylate glue, makes a glass-like bond), you cans simply use some red tread lock. If the fit is too tight, you can heat it to expand the brass part, but don't do it with a lighter. You need to heat the whole part or it will distortion and not fit after. A heat gun or worst case the oven is the best thing. You don't need to heat the steel part.

[martin2112]

Originally Posted by Kos-Mos

Sorry, I assumed that you knew how industrial press-fitting worked.

Never ass-u-me , even if you were right in this case. I guess that would be more of a transition or interference fit.

Originally Posted by Kos-Mos

They are usually heated around 200 degF before assembly. That makes the brass part expand a lot more than the steel part, thus making the fit snug or slightly lose.

It makes no sense to even heat the "male" part. Freezer or nitrogen, right?

Originally Posted by Kos-Mos

When going back to normal temperatures, the fit is very tight and usually will prevent the parts from going appart.

Yes, usually VERY tight. I wonder how it came undone. Lemon?

Originally Posted by Kos-Mos

Crazy glue will not work. The glue is probably only dry on the surface of contact. The reason why you had a hard time fitting is because the liquid glue cannot be compressed since it is liquid. When it breaks again (it will, crazy glue is a cyano-acrylate glue, makes a glass-like bond)

I will post as soon as it fails - promise! The stress on the bond is ONLY the force of the (weak) return spring, when pulling the valve to "closed". The strike (compression) on the valve will be transfered at the interface of the two parts, not via the bond. I'm worried about fatigue, though.

In any case, it will do for a sidearm at next Tuesday's game, while I wait for parts in the mail.

[martin2112]

Originally Posted by martind2112

Finally, what's my best bet (retailer) considering we're in Canada. I don't want a bill like this:
TM Release/Outlet/Output? Valve: 7.00 USD
+ S&H: 28.00 USD!

Anyone?