Grex Packing Seal (A120016)

This one piece seal works way better than the original. Doesn't leak and is much easier to clean.

Great packing seal easy to install. I would recommend anyone who has a grex gun to pick one up preemptively and get familiar and comfortable with both the packing seal and screw. The screw my gun came with was a little to lose causing more paint then was needed to find its way into the slider and body portion of the gun. If you are not comfortable or handy with tools/dealing with small parts I would just have spray-gunner service them for you in between projects. If you are wanting to do it on you're own my main suggestion is do not over-tighten the screw behind the seal. One of two things ends up happening if you over tighten. Either you crack the screw or compress the seal to much and you can easily damage you're needle trying to get it threw. I have found carefully adjusting it to where there is some mild resistance pushing the needle threw is a good place to start and you can easily give it a quarter or less of a turn in either direction to fine tune it. It does not need to be very tightly compressed to do its job. so again I can't stress it enough don't over tighten the screw. On my first attempt I had it to tight the needle would go threw but was way to stiff. Being used to working on small parts(I used to do fishing reel repair) I could be over simplifying but placing this seal and screw is really not hard its just not a brute force type of installation its very much finesse think more hand tighten then maybe a fraction of a turn with a screw driver. For reference I used a Klein non ratcheting screw driver with a Philips size 00 head, for the trigger screw I used a 3/32 flat head.(Klein Tools 32581) that's just my personal favorite for a long lasting precision tool. Spray gunner has a screwdriver set which has everything you could need as well.

This part is internal to the airbrush and as such wears out from time to time. It gets replaced after a total disassembly and deep cleaning. It also keeps paint from migrating backwards and gumming up the works. Again, Spraygunner is a great company where I know i can get these items.

I would give the packing seal 5 stars as a product itself. It did solve my problem of leaking paint down the trigger area. I gave it a 4 because this was the first time I replaced the packing seal on this airbrush. It would be very helpful if they had a link to a video showing how it is done. I did find a good video on how to disassemble and reassemble the Grex Tritium but it stopped short of removing the very last part. You guessed it, the packing seal. Ill give you a verbal tip on removing the seal: After you remove the packing seal screw if your lucky Grex tells me the seal sometimes falls right out. Not the case this time. I tried poking it out by inserting the flat back of an old needle through the front of the brush to no avail as Grex recommended. I made a mini hook from a piece of wire I had just a little smaller diameter than the .7 mm needle. After working and picking at the seal for quite awhile, it finally came out. It was deformed and worn looking even though the seal is only about .080 in diameter. I was surprised to find only one seal. The Grex part diagram showed two O ring seals with a note that said these two parts were replaced by one part. I did not know if my airbrush was old enough to have the two seals or a newer model which had one seal. Because the deformed seal I removed was the same color white and looked like the new seal I received from Spraygunner, I assumed I had a one seal brush. The new seal has a raised ring on the inner diameter. That detail goes in toward the front of the airbrush tip. The back of the seal looks flat. I was not sure of this because the replacement seal was not shown on the parts drawing from Grex. And there were no instructions included from Spraygunner. Just the two older seals and a note were shown on the Grex diagram. I must have guessed correctly because after cleaning the gun and replacing the seal in the manner I did, it is working like brand new again. Hope this long winded explanation about replacing a seal you can barely see helps those who have a Grex Tritium paint leaking problem from the trigger area.
Dale