Air Seal Nozzle Not Sealing Properly
 

What can I do to the air seal nozzle to fix this issue?

I know that it's my air seal nozzle that's not sealing the air properly because I did a compression test without the nozzle and the piston head and cylinder head was sealing in air very well.

It might be an issue with your hopup sleeve, then. Try testing some other sleeve brands.

By the way, your signature picture is currently over forum limit. Please reduce it accordingly.

what brand is it? Get the Prometheus brand.

Oh, and by the way, it almost never seals 100% perfectly with the air seal nozzle off the base of the cylinder head. So it's not that rare to have an airseal issue there.

But I really think it's the air seal nozzle. My gun is all taken apart and I have the gearbox open. So I doubt that it's the hop-up rubber sleeve, well as for now.

Yeah it's a Prometheus Air Seal Nozzle.

So you're saying that with my finger on the air seal nozzle while doing a compression test, I shouldn't be getting that good of air seal or not as good as if I just have my finger over the cylinder head without the nozzle?

If your nozzle has a tiny little o-ring in it...you can pick out the o-ring with a very fine flat screwdriver...lube it up and put it back in...(or swap the o-ring with a thicker one if you can find one that fits)

If it's a small slow leak...I'd leave it. If it was a bad leak and if I had tried several nozzles and none of them would seal, I'd swap the cylinder head.

it's almost never perfect, doesn't really matter whether you got a airseal nozzle with the O-ring or not. If it was such a tight airseal, then the airnozzle wouldn't be able to move.

Try putting it back in the gun first, and chrony all the shots. If it has a good airseal overall, the FPS deviation over 10 shots should be about 5FPS.

could it be the junction nozzle/hop-up?

Maybe your piston head o-ring?..

could be, but very unlikely.

What cylinder head are you using?

So how much loss are we talking about? Because when I'm trying to do a compression test, I can push the piston up the cylinder fairly easily with my finger over the air seal nozzle.

I'm using an ARS MASK Aluminum Cylinder Head with a sorbo.

The compression on my cylinders is always incredibly, with all my strength I can barely move the cylinder inside the piston, usually wont move past half way regardless of how much grunting and heaving I do.

I had problems with a Prometheus airseal nozzle on a Guarder cylinder head once, no airseal at all. Prometheus airseal nozzles have always worked flawlessly for me on Modify cylinder heads. I also always use double o-ring cylinder heads and so far with them (Guarder or Modify) I have never had any air leak around there.

One thing I always try to do is keep all the airseal components the same brand. So Piston head, cylinder, cylinder head, and nozzle. I usually go for Modify since they are fairly cheap and have amazing quality and as I said I have also had no problems with Prometheus nozzles on Modify cylinder heads. One mistake that a lot of people make with ventilated piston heads is to just put some thin lube around the o-ring and put it in. I have tried this and the airseal is never as good as when I lube it really well with thick lube. I use white lithium grease from the automotive department of Canadian Tire, comes in a tube for I think $4 or something, enough to last me (a regular gun doc) 6 months. I take off the o-ring, fill the piston head with grease, then put the o-ring back on, usually pressing lube out of the vent holes like spaghetti. Using this lube method I have never had a ventilated piston head with a good o-ring cause an fps reduction like some people have had.

If you put your thumb over the cylinder head and press the piston, and the seal is good, but then you put on the nozzle and repeat and the seal is bad, then yes its the airseal nozzle.

No, because I get a perfect air seal without the air seal nozzle and with my finger over the cylinder head.

How fast are you moving the piston? If you have a ported piston head, it takes a little speed to get the piston o-ring to expand and create a seal internally. If you're pushing it slowly, it'll look like an air leak because the o-ring isn't expanding.

EDIT: Nevermind, your last reply negates my answer.

Just tried that, I lubed up the o-ring with some silicone. But I'm still not getting a good air seal.

I'll see if Home Depot has any o-rings that are the same size but a little thicker.

you could do that. But as LUTNIT have said, using the same brand airseal parts are the best. I don't have experience with the cylinder head you are using, so I can't really help you here.

Before I make the trip over to Home Depot, would they even have the size of o-ring that I'm looking for or should I just go to Canadian Tire?

I meant the o-ring inside the nozzle...it's freaking tiny and I've not seen it at a hardware store...

If you find some let me know where you got them from please.

Tys

Last time I had to pick up O-rings just for work, they didn't seem to sell any individual sizes. Usually sold an entire set with different sizes in variety. Thickness may not have differed between them, but I'm not too sure. Keep in mind I was sent out with company money to buy crap for them, so it's not like I was really looking around.

Best bet would be to call ahead this way you're not burning gas for no reason.

Nope, you're totally right. I just went to the Home Depot website and searched for o-rings and they only sold them in kits. Not only that, they don't mention what sizes they come in in the descriptions. I just don't want to waste my time and go over there and can't find what I'm looking for because I'll be taking the bus. I don't own a vehicle at the moment.

Yeah, that's the o-ring that I removed and re-lubed from inside the nozzle. Really tiny, looks like it has an inner diameter of about 5.5mm and a thickness of about 0.80mm.

I found this one place on google, Apple Rubber Products Inc. I'm going to request a sample first before I make any purchases. Also, I don't know what their minimum quantity is but I'll ask them. If I do end up purchasing o-rings from them, would you want to go halves with me?

Try to remove the o-ring and use rubber sealing gasket. Wipe off excess gasket and test air seal. I haven't done this but read a lot years ago from filairsoft.com

What's the difference between Rubber Sealing Gasket and good ol' Silicone Grease? Can I get this Rubber Sealing Gasket from Home Depot or Canadian Tire?

A rubber sealing gasket is essentially a rubber washer, if I remember correctly. I don't know whether or not that would be beneficial, though, since a rubber gasket would be thinner, and if you're having an air seal problem that might not be the remedy you're looking for. I'm not too familiar with innerworkings, though, so it may be something to research upon.

I would like to think they're available at Home Depot. Canadian Tire might have them, and that's a big might. Like, 50 foot high might. If anything, you're best bet for some of those would be a Home Hardware, I find that they are really good for that kind of stuff. However, a lot of airsoft parts are considered "specialty" items by these stores, and then don't carry them, sort of like the .110 clips that attach to your motor. Some people find them in Canadian Tire, I had to go to a specialty electronics store.

Again, call.

Also, the websites for Canadian Tire and Home Depot are piss poor. Don't rely on them. I internet'd Canadian Tire about a hard-cover gun case, and they said they only had the bags. Lo and behold, I call there, and they have hard-cover gun cases on sale for 15 dollars.

Edit: Here's a rubber sealing gasket. Note that it's thin, not a tube-like ring.
http://www.allproducts.com/manufactu...l/product4.jpg

swap out cylinder heads and see if you get a good compression test with the nozzle. even if you test it with a stock one, just see what kind of air leak you get manually pushing the piston in the cylinder.

I just swapped out the ARS MASK Cylinder Head with a Prometheus Cylinder Head (same brand as the air seal nozzle) and I'm still getting the same air leak with the nozzle. But without the nozzle, with my finger over the Prometheus cylinder head, it's an air tight seal. Same goes with the ARS MASK cylinder head.

Yes to this! I'm still fairly new to AEG work, but I have definitely found this to be true. When your trying to seal in air, every tiny fraction of a millimeter counts. If you want to solve your issue easily, buy a Modify cylinder set from Airsoftparts.ca. I have used these twice now and the compression is very impressive....nearly perfect. Buy it and be glad you did.

Rubber sealing gasket comes in a tube and you apply it on the groove where you have removed the nozzle's o-ring. Wipe excess gasket and let it dry. While a silicone grease just lubricates and improves the airseal.

After applying, insert cylinder head in the airseal nozzle so it would flush the gasket, then wipe the excess.

So I would then have to get something that has a smaller diameter than the o-ring from my nozzle, right?

Well, with the o-ring in the nozzle, I placed a thin layer of silicone grease around the o-ring, about half a millimeter thin and now it's sealing properly with the ARS MASK cylinder head. Does anybody know how long this temporary fix will last me? Or is this fix good enough for the long run?

you don't have to get similar diameter of your o-ring. It's in a grease form, remove your o-rings, apply it in the nozzles groove, flush it with the cylinder head, wipe excess and let it dry.

Are you talking about rubber gasket sealing compound? Because that's totally different from a rubber sealing gasket. Also, there are many types of sealing compounds out there, would you know the specific one?

It's a gasket sealant. Much like those made by Permatex available at Canadian tire.