kcs g18c - slide cycle problem

[JohnnyDo]

hey guys got a problem perhaps you coudl help me out with.

I got a glock 18c used, it worked perfectly on semi but the slide would lock when comming into position to load the next round and fire. Being the guy I am who takes everythign apart I thought that it just needs a good cleaning. I took the slide off and stripped down adn cleaned every part in teh slide then re-lubed, then proceeded to put it all back together.

I'll make a note here saying that the chamber that holds the rocket valve (reed valve) was sticking a bit. I would pull it forward then release and it woudl simetime bind. I observed that when reassembling the gun the two springs used to push this chamber back is easily able to not be seated correctly and caused this binding action. Moving on, I re-assembled the slide and the chamber now moves freely. I load up a mag and try shooting. Weird as it sound my safety now works (move selector switch to middle possition) and so does full auto.

The problem now is tha the slide will not move all the way back to load a new round or when mag is empty to lock back the side. From feel, the slide is just as smooth or smooter as before. The selector switch seems to work and as said above my safety now works. From observation it appears that the slide is not getting anough gas to cycle correctly. I checked the rocket/reed valve inside the main chamber and it appears to move freely and not be binding. My understanding is this valve controls the gas to fire the bb/cycle the slide.

I have tried to dissassemble the slide again payign carefull attention to the rubber seal that the chamber rides on, and making sure it's well lubed. The gun still exibits the cycle problem.

Is it possible that this valve can wear out?
is it possible that the rubber seal is worn out (strange that it worked before the cleaning)?
does the rocket vavle have to be inserted or seated in a certain oriantation (ie direction)?

I've tried doing the search thing, one of the reasons i tried to clean everything and get the spring functioning to get my full auto working. Now the gun will not cycle.

any ideas?

[infernal]

The mechanic says to the penguin... Looks like you blew a seal.

[JohnnyDo]

ok would it be the round seal inside the chamber part #27 or something else?

I don't think it could be the seal on top of the mags as both mags worked perfectly before I started cleaning the gun. The round seal looks to be in pretty good condition as there are no rips or anything of the sort on it. But now that I think about it, I think i'm goign to take that seal off and try re-seating it again and see if that helps.

I'm still looking for other suggestions so please keep posting

thanks

[JohnnyDo]

SOLVED


Well the gun problems is now solved. I will give an outline bellow to help others.

KCS Glock 18c - stock, no upgrades.

Problem:
This is two fold. I got the gun used and it only fired in semi auto. When I choose full auto, the gun would fire one round (which was chambered) then the slide would stop about 1" from battery position venting all the gas in teh mag.

Problems found during diagnoses:
Because this gun was used, it was well worn in some parts. The internals of the gun were well lubricated but there was alot of dirt and grime. Personally this is not a good thing for any gun real or airsoft not to mention the gun was already not working correctly. When I took the slide apart to all it's components I found that one of the previous owners has already gone inside the gun by wear marks from the varrious screws etc. I eventually found that the springs (part #23) were not fully seated in their correct position. The springs where binding against the main chamber (part #22) and the slide. The result was the chamber (part #23) did not slide smoothly. This is a good time to say that when you buy a used gun make sure you look closely inside the gun for previous "gun doctors" hehe. Anyways, the spring did/does have a kink on one end. After much frustration I was able to bend it back to 90% of what it should be.

Action taken for repair:
As above I took teh slide apart to all it's varrious peices and used cotton swabs and silicone oil to clean everything. This way I know it's in good clean shape as well well lubricated. Apon re-assembly of the slide I made sure to place the springs (part #23) in correctly. This procedure totally fixed my gun as I know has full auto capabilities and my safety (middle selectro switch setting) functional.

Problems post assembly:
After the gun was assembled I found that the slide woudl not cycle 100%. It would fire, but the slide would not move back far enough as to load the next round.

Action taken for repair:
I later found after taking a very good examination of another glock 18c along side mine, that I placed the seal in the main chamber (part #27) in backwards. I woudl suspect that this changed the internal volume of the chamber enough that enough presure would not build up to cycle the slide. So I wanted to give you guys note that make real good sure that you follow the internal parts diagram of any gun you work on and closely follow the orintation of any and all parts as this will affect the performance and opporation of your gun. Anyways, after I found my problem, I reseated the seal correctly. Once everything was back togethter again the gun now works flawlessly.

Overall impressions:
I must admit that gunsmiths really do need more credit then I'm sure most of us give them. I am not a stranger to taking stuff apart, fixing it, and putting it back together again. However this has taught me a lesson that you really have to pay attention to what your doing. Althoguh anyone can take guns aparts, you need a special gift to find problems that are right in front of you and be able to know how to fix it. Props to all gunsmiths out there. Although most of you will never take yoru gun apart, it is a pretty fun way to spend a weekend, never know what you might learn.

JD

[TheLair]

I am having the same problem as you except with my KWA G18c. It has a metal slide and barrel. Do you think it could be the same thing with the nozzle. Or could it be the springs?

[Shinjin_MC]

techically the middle position on the 18c is the disassembly position, not the safety
glocks dont have em

with the metal slide and barrel, you need a stiffer recoil spring
do you have one installed?

[TheLair]

I don't but I am getting one to see if it helps

[Shinjin_MC]

ah
theres your problem
the stock recoil spring is a bit too weak to completely bring the slide back to firing position
it jams a few mm back of the firing position and the hammer wont drop
which requires you to push the slide back forward
happens more in full-auto fire than semi

[TheLair]

That does happen sometimes, but that isn't the problem. The slide only blowsback about a half an inch so it doesn't chamber the next round.

[TheLair]

I am getting a better recoil spring sent to me. So I have that solved.

[Shinjin_MC]

oohh....it sounds youve got something else happening then
the recoil spring would aggravate the problem, i think, since at the moment the gun isnt even completing a full cycle

[JohnnyDo]

look at the seal inside the chamber the loads the bb and gas

make sure that chamber moves freely, if it does not fix the problem

check the slide under the selectro switch for cracks ... bend the slide outward a bit at this point to see the crack

make sure the springs which push the chamber are not kinked

put a drop of silicon oil on top of the mag seal where it mates with the chamber .. if it's too dry it might be too much friction to allow the slide to move back witht he chamber (loading next round)

these are all problems with my glock and once looked at fully fixed the problem ... well I still ahve to get a new slide but still.


i think the best thing to do is to narrow down which functions of the gun work, if you can manual chamber a round and fire it normally the fireing mechanisim works. if the slide doesn't move back far enough it's a seal, presure, friction issue. if the slide moves all the way back but doesn't move forward it could be the slide is cracked, recoil spring, etc.

[TheLair]

I did have a kink in one of the springs, and I got it fixed. I also looked at the nozzle thing part #27 and I haven't touched it. But when I pull the rocket valve out it is very sandy sounding, and doesn't slide back in place very easily. Also I lost the allen wrench do you know a place that sells them?

[JohnnyDo]

well getting that small of a allen key is goign to be a bit hard, I can dig out my calipers and tell you the exact size of it if you really want to buy a new one as most allen key sets at walmart and canadian tire won't ahve one that small. Or just fint a jewlers flat head screwdriver and *carefully* unscrew it. this is what I did when i first got my gun and as long as yoru carefull you won't strip it.

as far as the rocket valve.. not sure why it would be scratchy sounding or not going in smooth... it woudl probably be worth while to take out the pin that hold the valve and spring in place and clean the inside of that chamber really good. taking apart the slide mechanisim is really easy to do .. just make sure you look at a parts diagram while yoru taking it apart to fully relize how to put it back together again.

[TheLair]

I'll try that thanks for the help