Problem with Micron MAC Valve

[crewchief227]

Hey guys it has been a looooonnnngg time since I have been here, but hey I was busy painting. LOL Anyways I was doing a full breakdown cleaning of my CM-C+ V2 last night. So long story short when I was putting it back together I got a little air leak at the nozzle, no big deal a little chapstick fixes that, but when I had the entire nozzle off I decided to run air thru it and noticed I was getting inconsistent air coming from the air hole at the bottom. But when I screw the MAC valve all the way open until you get some resistance the spitting of air goes away. Turn the MAC valve in like you are adjusting pressure down and it starts spitting again. That is when I was like crap, that must be the reason I was getting dots and inconsistent spray patterns.

So anyways I have never broken down the MAC valve. I always figured it was in the air path and really never needed breaking down. Would like some tips on breaking down the MAC valve (if you can) before I do something stupid and have to send it away to Iwata for repairs.

 

[Malky]

I would guess that part 30 in the diagram here may be damaged or has perished, quite possible if it's rubber, since it is listed as a part it obviously must be possible to remove part 29 to replace it, you'll need a very thin small wrench to pry the nut part just above the air adjustment screw, you could also just have dirt possibly form your compressor in the air channel, this does happen form time to time depended on how ell your air is filtered, you could try cleaning the channel with a tiny inter dental brush or a piece of wire thin enough to pass through the hole you can see at the front with the head removed, do this with the valve fully open, another possibility is that the part that enters the channel could have gunged up lubrication on it, still requires cleaning.

I would personally clean it, then leave it fully open permanently and use an external/inline MAC valve instead, external ones are not that expensive and the up side is that if anything goes wrong with it and you don't have a spare, you at least still have the use of your brush, I've had one brush with the built in MAC and the biggest drawback for me just because of how I held the brush was that I frequently nudged the valve open accidentally and ended up with an unwanted blast of paint, so I stick external valves, unfortunately on any airbrush a built in MAC is just something else that can go wrong

 

[crewchief227]

I doubt it's dirt from the compressor as I have a 6 gal SilentAire with a oil filter, followed by a moisture filter, followed by a grip filter at the airbrush. I just wasn't sure if I could wrench that nut at the bottom cause it looks so flush that it almost looks like it was machined as part of the body. I have seen that diagram many of times as I use it to order parts from Coast Airbrush. It's just not a very accurate diagram. I use a external MAC on my other brushes and I actually like the integrated MAC valve as it sits perfectly with my grip. But ya it is just another thing to go wrong and lets face it Microns are beautiful but finicky at times. I'm going to leave it open for todays spraying and take another look at it tonight as when I screw it all the way out there is some gummed up stuff on the threads that I have been wanting to clean for awhile, but being a workhorse that I use 4-6 hours everyday I don't worry too much about it looking "pretty". LOL

 

[Malky]

I doubt it's dirt from the compressor as I have a 6 gal SilentAire with a oil filter, followed by a moisture filter, followed by a grip filter at the airbrush. I just wasn't sure if I could wrench that nut at the bottom cause it looks so flush that it almost looks like it was machined as part of the body. I have seen that diagram many of times as I use it to order parts from Coast Airbrush. It's just not a very accurate diagram. I use a external MAC on my other brushes and I actually like the integrated MAC valve as it sits perfectly with my grip. But ya it is just another thing to go wrong and lets face it Microns are beautiful but finicky at times. I'm going to leave it open for todays spraying and take another look at it tonight as when I screw it all the way out there is some gummed up stuff on the threads that I have been wanting to clean for awhile, but being a workhorse that I use 4-6 hours everyday I don't worry too much about it looking "pretty". LOL

I see, well it sounds like some that gummed stuff has made it's way into the air channel, obviously just a little since it's only a problem when you restrict your air with it, try cleaning the channel anyway from the front as I mentioned to avoid trying to remove the valve, after you clean it give it a tremendous blast with the head off and it should be fine, I wouldn't want to try to remove the valve, but clearly if there is part listed for it for it, it has to be possible, I've had to clean to clean an external one and it's exactly the same except it's fed into the side of the quick connect.

I hope you get it sorted, keep us updated

 

[crewchief227]

I was thinking of posting pics of the process tonight. Thanks mate

 

[Malky]

I was thinking of posting pics of the process tonight. Thanks mate

 

[crewchief227]

Okay after having to break it down twice I finally got it resolved I think. I broke it down and the two O-Rings in there looked in perfect shape. So I ran a dental brush thru the airways and it kept coming out clean. So I then backed it out as much as possible and really gave the threads a good cleaning. I put a little SuperLube on the threads and it was a lot smoother, so I re-assembled. With the fluid head off I hooked her up to some air and sure enough the problem persisted. I made a quick YouTube video so people could hear it and after that I took a super thin layer of the SuperLube and coated the O-Rings. Assembled it again and still heard the problem, but it kept decreasing as I worked the valve all the way in and out. After 5 minutes of working the valve with air on I got it resolved. Put the head back on and ran some straight cleaner thru just to check the atomization and it looks pretty good. I'll give it real run tomorrow with paint. Here is a pic of the O-Rings.



If anyone is curious about how the problem sounds I can post the video as long as it stays here on the forum.

 

[jbuckley421]

Don't mean to hijack the thread, but I was just getting on here to ask if there's any need to clean the mac valve? I'm in the process of "deep cleaning" my cm-c+, and I've never taken the mac valve apart. there's some black gunk on the screw, but I'm not sure if it's just grease and not the result of paint or something that will affect performance. If its just lube or grease, I'll probably just leave it. However, if it is something that needs to be taken care of, I'd really appreciate some input!

 

[crewchief227]

I've had my Micron for almost 5 years now and this is the first time I have ever had to break down the MAC valve. I just noticed the weird air spitting problem while I had the head off. But the good news is a regular crescent wrench can take the MAC valve off as that nut is a hair bigger than the adjustment screw, and there is really nothing to it. I was always afraid to break down the MAC valve, but now that I have done it, I will do it more often just so that I keep those O-rings lubricated.

 

[jbuckley421]

I've had my Micron for almost 5 years now and this is the first time I have ever had to break down the MAC valve. I just noticed the weird air spitting problem while I had the head off. But the good news is a regular crescent wrench can take the MAC valve off as that nut is a hair bigger than the adjustment screw, and there is really nothing to it. I was always afraid to break down the MAC valve, but now that I have done it, I will do it more often just so that I keep those O-rings lubricated.

I've only had mine about 6 months, but I use it A LOT. Might be worth cleaning I suppose. Side note: Were/are you in the Air Force?

 

[crewchief227]

I was a US Army AH-64D Apache Attack Helicopter Crew Chief.