Maintenance och leak prevention for gas powered airsofts

The following is a guide for how to maintan your gas airsoft as well as how to fix leakages if they arise. GNBB, GBB, GBBR are different types of gas weapons but for simplicity, hereon we refer to them as GBB (gas blowback) as many of the maintance steps are the same (including CO2 and green gas powered weapons). GBB are more prone to faults compared with AEG (electric airsoft) but most faults are easy to fix and prevent.

Products suitable for maintenance, lubrication and performance

General usage

GBB are sensitive to ambient temperature and can not function in low temperatures. Generally under +10°C GBB wont function as designed. There are more powerfull gas blends that sometimes can be used (so called red och black gas) but it´s not a guarantee they will work and they also increase the wear on the GBB.
The gas from the magazine expands while firing a GBB and this results in a rapid cool down of the pistol and surrounding air. Excessive rapid fire will cause to much cold and this can affect performance (generally for example there is not enough gas to propel every BB in the magazine, bad working blowback etc). Therefore firing a whole magazine in one rapid succession may not always be possible. GBBs with small magazines like Luger and 1911 are more sensitive to rapid fire problems.
When filling up your magazine the gas container should be placed up side down with the nozzle down towards the magazine. There is an O-ring that the gas container nozzle fits onto, this O-ring should be lubricated regularly with silicone oil. Filling of a gas magazine usually takes around 2 seconds.

Maintenance

Gas weapons are sensitive to dirt and contaminants. The mechanism must be able to work without hindrance and with well lubricated surfaces. Wipe you gun clean with a piece of cloth. Metal parts that have movement against each other should ber lubricated with silicone oil. O-rings and gaskets should be lubricated with silicone oil och silicone grease. Especial importance point of lubricating is nozzle and its different sliding surfaces (different types of nozzles pictured above). You can not use petroleum based products as they can damage rubber and plastic parts of the GBB. Metal on metal surfaces can be greased with lithium grease as well. Excessive lubrication can have opposite effect with creating to much drag for the mechanism.
Green gas magazines should be stored with a small amount of gas in them! If they are stored without gas they will start to leak as the gaskets and o-rings dries and can be off set (usually this is remedied by re lubrication). Magazines over long periods of time will leak some, so make sure to refill the every now and then if you don´t use them for a long time.
CO2-magazines should not be stored with CO2-cartridge attached! CO2 does not contain silicone oil (green gas do) and will dry out the seals. So always empty the CO2 magazine of gas and remove the cartridge. Put some silicone grease on the sealing that pushes against the tip of the CO2-cartridge after use.
The barrel is cleaned with a rod and a piece of cloth. Adjust the hop up to zero so you don´t damage the hop up rubber. If the pistol have a fixed hop up you cant drag the cloth against it. Do not lubricate the inside of the barrel. If you have contamintents drag the barrel clean with cloth. If the hop-up rubber gets lubricated it will not cause the drag needed to sping the BBs. If it gets excessive lubricated fire a few mags trough it and the lubrication will wear away.

If your GBB experience problems, FAQ.

(1) The weapons behaves differently after a time of storage:
Usually this is remedied by firing a few magazines. Fill the magazine with gas, keep the slide catch down and fire a magazine or two (without BBs). Spray some silicone oil on the nozzle and magazine valve. Usually this kicks the GBB back to life. If this doesn´t fix the problem; disassemble the slide and wipe clean with cloth and put a thin layer of silicone oil on moving parts and surfaces. Assemble and without a magazine inserted cock and uncock the slide a couple of time so the lubricant is spread evenly.

(2) Magazine seem fine but nothing happens when you press the trigger:
Check the safety (manual tells you where it is). Usually located on the side of the pistol, some Glock-models have them under the barrel. With the magazine filled with gas, remove it from the weapon and gently tap the upper magazine valve and check if gas comes out, but be careful as the gas is very cold so wear gloves or use a screwdriver or other tool that keeps you out of harms way. If gas comes out, test the pistol again as sometimes the gas preussare is so high that the hammer in the weapon don´t have enough force to press the valve in.
If still nothing happens, unscrew the outlet valve from the magazine (remove gas before hand!), clean the valve up and make sure it can move freely. Lubricate and screw in. You can test with having the valve fully seated or untread half of a revolution, that makes the valve pin come closer to the pistols hammer (given that the unthreading don´t start a leakage.
It can also be the pistol that malfunctions, easiest way to elimande the magazine as a culprit is to switch to another magazine. Always a good start with any GBB diagnosis to test with multiple magazines. If still nothing happens is probaly some malfunction with the hammer (to short or damaged) or trigger mechanism.


(3) Magazine leakage:
A classic, happens to everyone. Most of the time, it is enough to let the valves "seat" themselves. Spray thoroughly with silicone spray from the outside where you see or think you see rubber parts on the magazine. Exercise the valves (empty of gas) by pushing them in and out a few times. Fill the magazine, unfill and fill again until the leak stops. Usually its not a broken o-ring but only a bad lubricated one or one that is not seated correctly. Remember to keep the valves pressed in when lubricating them, otherwise the oil will not reach the entire o-rings. Hold down, spray, then push the valve in and out a few times to soften the entire rings.
The next step is to grease the o-rings. Try to find out where the magazine is leaking, usually it is at the bottom gasket or in the valves. Use exploded views to find out which o-rings are available. You can read about examples at the bottom of the page.
Disassemble the magazine to access the leaking o-ring or gasket. Then lubricate with silicone grease (best) or silicone spray. You can use a cotton swab to grease the valve, then you usually don't have to take apart every single part. Assemble and test shoot. Now the magazines almost always work and have stopped wheezing. If the o-ring is broken or continues to leak, buy new o-rings. It can be good to have a small supply of o-rings at home. Try to get good quality o-rings. Sometimes it seals better if you use slightly thicker o-rings.
A final solution is to use blue silicone/gasket silicone. This sets like glue and becomes completely tight. However, it may be virtually impossible to disassemble the magazine again, so this should only be used as a last resort and the surfaces must be degreased before hand.

(4) All gas is released after a few shots fired:
This can have multiple problem sources. First of al check the magazine for leaks, malfunction valves or improper insertion. Test with another magazine if possible. Make sure you use the appropriate green gas, to low pressure (or to low ambient temperature) can cause the slide to not blowback enough and making the valves stuck open.
The GBB can also malfunction due too to high friction between slide and body. Make sure the sliding surfaces are correctly lubricated with silicone oil or lithium grease. Exercise the slide forwards and back a few times.
If it´s the weapon that is the problem:
- Check that the piston inside the nozzle seals properly. Hold a finger against the inlet hole for the gas and blow in the nozzles front end, the piston head should then seal completely without air letting out. If it doesn´t, lubricate with silicone grease or replace o-ring.
- To high friction between nozzle and slide/mechanism. Can be improper lubrication, dirt or minimal fabrication errors. Lubricate and clean. Check that the are nor moldings lips that can cause an error on the nozzle. Make sure the nozzle moves freely, you can use fine sandpapper to adjust any imperfections.
- To high friction in sliding surfaces, to strong recoil spring that pushes the slide forwards. Check for dirt or imperfections at the recoil spring under the barrel. You can test with a stronger green gas and check if that solves it. - Check the ambient temperature or if the pistol/magazine have been stored in a cold place.
- BB feed errors can cause these errors. Check for dirt or other issues with the magazine, magazine lips can be damaged.

Example for magazine maintenance; SRC G36 GBBR

The following is an example for maintenance of a GBBR magazine. There are many different types of magazines but often the construction principles are similar. After removing the plastic shell this is the inside of the magazine.
A (on the underside) is the filling valve, B is the firing pin for the discharge valve, the valve itself is accessed if you unscrew the firing pin or from the inside, C is the gasket between the parts of the magazine (the gasket is on the inside, not visible), D is the gasket against the nozzle.
On A, you should see that the tiny o-ring is still there, it should seal between the valve and the gas bottle. However, this o-ring usually flies away and it does not fulfill a war-determining function. Can cause leakages when filling up the mag
At B, you don't have much access from the outside. If you want to unscrew the firing pin, you need a special key, alternatively you can improvise with some self-developed tool (slim scissors, cutter for a piece of sheet metal or the like). However, you can care for the valve from the inside, see a bit down.
C is not accessible from the outside (you can't even see it), see disassembly a bit down. It is important that you lubricate with silicone oil. Also check that it is not damaged. Also check that the magazine tabs are intact.

When disassembling the magazine, first check that the magazine is completely empty of BBs and gas, press B until nothing more comes out. Then press out the thin metal pins at C, press with some narrow tool. Now you can pull the magazine halves apart and you will see the o-ring at C, which you should lubricate with silicone grease, as shown in the picture on the left.

If you look into the opening on the same part and the pressure on B you will see the o-ring for the exhaust valve, see the picture in the middle. With a cotton swab dipped in silicone grease, you can apply grease to the o-ring. Add enough grease and make sure that no "fluff" from the top gets stuck in the o-ring.

If the o-ring at the bottom leaks, you can unscrew it and grease the small o-ring. If that doesn't help, it's almost best to replace the valve.

Example maintenance GBB, WE M9

Here is a brief guide on how to lubricate your GBB. The weapon we are showing is a WE M92 GBB but the technology is usually similar to different pistol types.
The guns are relatively simply designed, but they work with very small tolerances, e.g. the nozzle one millimeter wrong, it can mean that the weapon is completely unusable. If an o-ring is put on crooked or with debris underneath, the gun can leak even though you think you lubricated everything correctly.
When you lubricate, you start by wiping away dirt and old oil and then apply a thin layer.

We start by disassembling the slide. Start by removing the magazine from the weapon and make a slide movement ("cartridge out"). When the slide is pulled back, hold it there and bring up the last-shot lever (above and just behind the trigger) so that the slide is held in its rear position. Then you pull down the slide latch that sits in front of the last shot latch. The appearance of this varies between different weapons, but you can usually find it easily.


We can now lower the last shot latch and advance the mantle so that it slides off the body itself.
You should now be sitting with something similar to this:


Now we lubricate the nozzle. It is an extremely important part that controls air flow, feeding and more. It is on most weapons made of plastic and is sensitive to cold and shock. Do you shoot e.g. two magazines in a row the nozzle has become very cold and brittle, you can save the nozzle excessive friction and wear by lubricating it. In some cases, it will not work at all if it is not lubricated. Even if you lubricate the nozzle perfectly they have a tendency to break, you have to be careful with it and not shoot too much in quick succession etc. Inside the nozzle are various springs, a piston head and some other small parts. The easiest way to access these is by spraying silicone oil into the open hole at the bottom of the nozzle. You should also lubricate behind the hole and make sure that the silicone penetrates the spaces that are not directly visible to the eyes. To access "on top" of the nozzle, it is usually convenient to spray towards the two springs (often there is only one) that hold the nozzle back, you can see them going along the sides of it.


We also carefully bring the nozzle forward and spray silicone on the surfaces that were not visible before. Note that on some pistols (e.g. SRC M92) you absolutely must not pull the nozzle forward too far, then the nozzle spring will be destroyed and you will have to replace it.


The spring guide may need a thin layer of silicone oil from time to time so that the spring runs smoothly, however, you should not lubricate this part too often as dirt can get stuck in the silicone. At the back of the mantle (underneath) it must also be lubricated, extremely important on some weapons. Not really on this variant but it doesn't hurt to show it in this guide anyway. The reason why it can be important is that the part slides over various mechanical "switches" which can affect feeding, automatic fire and more. It is the silvery part that is visible. If you see that it becomes worn over time, it means that some part (e.g. latch) is against it during use and it is therefore a sliding surface and needs to be lubricated.


The sliding surfaces, the surfaces of the gun body itself against which the slide slides must be lubricated for the blowback to function properly. Exactly what the sliding surfaces are depends on the gun and you may have to sit and pull the slide back and forth a few times to see where it should be lubricated. What you can do is spray some lithium grease on the surfaces you think and then you pull the mantle back and forth, once the grease has been smeared the surface should be lubricated. If the grease is intact, you can take it a little easier as dirt easily sticks to grease.


On the right side of the weapon, the trigger usually has a small piece of metal that sticks up and this should be lubricated. If the trigger feels a bit "choppy" sometimes, it can be worthwhile to unscrew the grip surfaces, alternatively to just spray a little silicone oil on the side of the trigger "spike". In the picture below you can also see that the paint has come off a little on the weapon and this means that the mantle rubs against those surfaces, so they must be lubricated.


The magazine is almost more important to lubricate than the gun, in addition, leftover silicone oil from the magazine's gaskets is spread quite well in e.g. the nozzle when firing. There are two valves on the magazine, one upper and one lower. Here you see the lower valve. This has several o-rings that must all be lubricated. Partly, it is the one that the gas bottle's nozzle is pressed against, i.e. the very small "inside" valve. Just spray down some silicone oil. Then you have the o-ring that lies between the head of the valve and the magazine. Further down the inside of the valve there is a minimal ring that is difficult to access; the easiest is to take a pointed tool and press down on the "spike" that sits in the middle of the valve while spraying silicone down. By pressing down on the spike, the valve is open and the silicone can access the innermost o-ring. In some cases, you need to unscrew the valve to get access to fix any leaks. You then simply take a screwdriver and unscrew it.


Now let's take the upper magazine valve. Spray silicone oil into the "hole" on top of the magazine while pushing the valve in with something pointy (screw in the picture). Then push the valve out and in several times so that the silicone really reaches all the o-rings, if necessary spray in more silicone oil. Sometimes the entire valve must be disassembled and this may require special tools. On some valve types, however, you can access lubrication surfaces by spraying in silicone oil from behind, roughly where the screw is pointing in the picture.


The magazine also has an o-ring that you cannot access from the outside. If this is leaking, you notice it most easily by hearing a hissing noise from below, but it continues even if you block the lower valve. You must then pull out the pins that hold the magazine together. Is a little different depending on the magazine, but below is a common solution. The sprints can only be pulled out in one direction, do not use too much force as you will then destroy the metal. When the pins are to be reinserted, insert the end of the pin that is not grooved first. With the pins out, in this case you can pull out the bottom of the magazine, other magazines also have a screw on the underside that must be unscrewed.


Here you see the o-ring.


Remove it and inspect the surface it rests against, no metal shavings or dirt must be there! Carefully clean the ring and the mounting surface of the magazine. Then grease the o-ring and put it on, it can be a little tricky and you must not stretch the ring too much or create cracks in it, do not use sharp tools. Use plastic tools that are blunt if your fingers won't do. In the picture below, you can see a small silvery dot on the surface where the o-ring should sit. In this case it was a piece of aluminum that was left over from manufacturing.


We will now turn our attention to the rubber part that sits on top of the magazine. It can crack if it is not lubricated (often in combination with cold and there being some misfeed so that a ball is pressed down against the rubber). The picture below shows that rubber part circled.


You usually access it by pulling out one or two pins (as with the bottom part above).


Here you see a picture of the upper valve with the magazine tabs removed. We sprayed the upper valve earlier but it is partly from this angle, try pushing the valve in and you will sometimes see that an o-ring inside the valve is made visible.


You will probably learn what to lubricate and at what intervals. At the same time, it must be remembered that gaskets are a perishable product that needs to be replaced or repaired over time. If you can't bear to buy o-rings, they can sometimes be replaced with e.g. sealing silicone.