Iwata HP-CS issues

mgh:

I have had this problem since the airbrush was brand new.  I find if I loosen up the hose connector at the bottom of the airbrush a tiny bit, the problem goes away, but this causes a bit of air to leak out the loosened hose fitting.  Looking up into the airbrush body through that air port, I see an o-ring or packing that looks kind of squished.  I think it is interfering with the free movement of the air plunger.  The instructions give me no clue as to how I can get at it and replace it.

Try loosening your air hose connector just a bit, there at the airbrush and see if the trigger return problem goes away.

And if you figure out how to fix it, please let us know!

I have the same issue with mine, and like Chuck, have suspected the mushy o-ring but haven't taken the time to properly troubleshoot the issue. "Mushy" also defines the up-down action of the trigger, in my case.

So that makes 3 of us looking for an answer, which may well end up being a new o-ring???

I agree.  But how to get a new one and get the old one out remains a question.

I have found that putting a smidgen of that blue lubricant in there, and behind the trigger,  will help for a time.

Hey thanks!

I am heading to work soon, but will look for that O-ring tomorrow.

The upper air valve seal (part 7 / IWS-5801 in the Iwata parts diagram) will swell in the presence of cellulose / lacquer / strong thinners, the increased resistance will make the air valve spring reluctant to return the piston to the up / closed position.

If the seal is removed & left for a day or two, the thinners should evaporate off & return the seal to normal.

I used to disassemble my Iwata AB's (including my HP-CS) and clean every part after every session.  

Several AB experts told me not to because constantly disassembling AB's results in premature wear & tear, misalignment, etc. They asked me to disassemble only when an AB doesn't spray well.  I haven't disassemble any of my AB's since last August.  I just shoot Windex or IPA and backflush, followed by shooting distilled water, after every session.  They are all working fine so far.    

Thanks for the ideas Chris and mylairjunkie.

Bubbles in the cup usually mean a blockage or bit of dry paint in the nozzle. Sharpen up a cocktail stick or similar, soak the tip in cellulose thinner and gently insert the stick into the nozzle a nd  twiddle it to clean it out VERY GENTLY!

I had the squishy plunger too, its usually caused by thinners getting into it as previously mentioned by milairjunkie.

You can dissasemble the trigger assembly by loosening the nut on the bottom after you pull out the trigger. I just take a tweezers and insert in in the 2 slots on the nut and turn out. I have found a bit of old dried paint in there before. (don't know how it got in there)

Nathan, I never could figure out how to get that air intake valve apart. Just tried it, worked like a charm. Never thought of using tweezers for the spanner slots. :)

Thanks!!

Greg

Nathan, I never could figure out how to get that air intake valve apart. Just tried it, worked like a charm. Never thought of using tweezers for the spanner slots. :)

Thanks!!

How did it go pulling it apart and back together?  Did it help your trigger action?

I haven't looked for the part to see if I could order the O-ring, but I once looked for the O-ring behind the nozzle, and most places wanted $7-8 for shipping!  Hobby Lobby has some parts, but did not have any O-rings.

Just checked Chicago Airbrush Supply.  They call that part "packing valve piston"

www.chicagoairbrushsupply.com/i5801paairpi.html

At least they have shipping for $4.

It helped. Just don't tighten the nut too much when you put it back together.

This parts diagram does not even show an O-ring in the assembly below the trigger.

www.chicagoairbrushsupply.com/eclipseparts.html

Sure it does. #7, and I think another one in the #8 assembly.

mgh

How did it go pulling it apart and back together?  Did it help your trigger action?

Sorry late reply, mgh....

Gotta be careful with the retaining nut so the spring doesn't send in in orbit when the threads disengage.(guess it's called 'air valve guide screw, part #11 on the parts diagram posted above). A bit dodgy getting it back in, and again, gotta be careful the spring doesn't send it flying.

After initial reassembly, still had a slight trigger mushiness (mine comes and goes, it seems). It's been a couple days since I did this, just went down and checked and the mushiness is completely gone for now. Maybe has to do with what mylairjunkiementioned above about #7, packing valve piston being cleaned and allowed to dry thoroughly?

Thanks for posting that parts diagram, makes it lots easier to discuss this.

The o-ring I happened to be talking about is down on the hose connector, not on the brush itself. Sorry if I confused the issue. Confusion is my normal state.

Greg: I have not pulled mine apart yet.  I thought it was starting to move a bit more freely, but it is not.  Any other tips for me, other than being careful about the spring?  Does it come out in 5 pieces?  Did you let the parts dry out, or did you clean them up with something before re-assembling?

NathanT: check out the picture of part #7 in the description of each part below the diagram.  #7 is the "Packing Valve Piston".  The picture shows something coming up from the center of this.  It does not look like an O-ring.  So when you pulled yours apart, this Packing Valve Piston was in fact an O-ring?

Maybe I will have the time to get to the airbrush today.

Thanks for all the help.  I will be very happy if I can get this fixed!

mgh

Does it come out in 5 pieces?  Did you let the parts dry out, or did you clean them up with something before re-assembling?

4 pieces. The packing valve piston (part #7 on the diagram) is firmly attached to the guide body (part #8). It appeared to be more plasticllike than rubber.

I threw them all in my ultrasonic cleaner, along with the rest of the the brush since it was was torn down anyway. Didn't allow to dry (probably should). It seems to be fine for now.

I don't plan to tear down that lower valve assy routinely, sooner or later I'd lose the nut.

Hope this helps somehow.

Yes, that does help.

I must have gotten parts #8, 9, 10 & 11 out, but did not identify #7.  Don't feel like pulling it apart again right now :)  Upon re-assembly it worked much better.  Have not yet tried to run anything through the brush.

NathanT is correct that there is an O-ring as part of the assembly that is part #8.

I can say for certainty today that the dis-assembly yesterday did not help at all, the trigger is just as sluggish as it was before :(

And after mine sat dry for a few days, a bit of trigger sluggishness has returned. I've tried a drop of Iwata lube down there before, but never disassembled. Next step for me is to disassemble the assy again, and lube it up a tad inside.

Have you checked if the top of the rod is moving freely through the bottom of the brush boday? I didn't think to do that when I had mine torn down, will check it when I tear it down again. If there is any resistance, maybe run a pipe cleaner though it.

I just remembered that Iwata recommends a drop of lube up at the top of the trigger mechanism. I haven't done that in a long time, will be doing that too.

Mine isn't that bad, it is just there and doesn't feel exactly right.

Wow, I am getting real frustrated with this Iwata.  It has worked flawlessly for  close to a year and a half, but now I am having weird problems.

A few weeks back I started having problems with what I thought was clogging, just could not get it to spray evenly, or flow was poor, or no flow at all.  I clean it up after every use.  Today picked it up, and it would not spray a thing.  I cleaned it all up, even ran some lacquer thinner through it.  Though experimentation, I figured out that sometimes when I put it back together it worked, and sometimes it did not.  Mostly, it did not.

I am not talking now of disassembling the piece below the trigger, I am only talking about regular cleaning break-down; taking the tip, nozzle and needle out, and re-assembling.  Sometimes it blows air back through the cup, like it is completely blocked.  When it is not spraying, I can loosen the needle, and pull it back a tiny bit, and that will not make it spray, so it does not seem to be from the needle.  Inspecting the tip I can see no issues, and if there was an issue with the tip, I would expect it to be consistently bad.

During 2 sessions, I have pulled it apart at least 30 times, running only water through it to test it.  It is inconsistent as heck.

I am trying to backtrack to see what I have changed recently.  I did put together a homemade spray booth, and after that used some enamels thinned with mineral spirits, and some thinned with lacquer thinner for the first time.  Recently I put a small drop of Iwata lube in the top of the trigger.  I put a new needle in it about a month ago when I first started having problems, even though I could not see anything wrong with the old one.

This has me baffled, I have had this apart dozens, probably hundreds of times through the months with no issues.  Now I seem to have issues every time I try to use it.

Anyone have any ideas?  I have not looked up Iwata support on the web to see what help they may offer.  Has anyone had experience with their customer service?

Thanks everyone!

mgh, have you consider contacting Iwata customer service and send your airbrush back to them for a checkup and possible repair? It may be time you have to do it.

At least, send them the description of problem you wrote here.

I have not, that may be what I need to do next.

Hi!

I do not use any type of super lube on a air valve ever, nothing but problems! I use a drop of thin machine oil, you can find a needle applicator of the oil at a hardware store and apply a couple drops to the top or pin of the valve once there shows a problem, and that is only a couple times a year.

Enamel thinners can cause the rubber o ring around the valve pin can swell and impede the pins movement.This oil will help. also dropping some windex on it may help too, but I recommend the oil.

Dang, I used to have one of those applicators.  I would try anything right now (though I have not yet called Iwata).

When I first pick up the AB, the trigger will be working fine, but it only takes a few cycles with the trigger, and it will be sluggish again.

mgh, FWIW, I tried modelmaker66's 3-in-1 idea tonight on mine as suddenly it was stuck spraying air when I fired up my compressor. Took it a few minutes to do whatever it did, but for now at least it is as positive an action as when it was new out of the box. Hope it stays that way.

(then of course my Harder Steenbeck started sticking, but a thorough cleaning solved that as it always seems to with that brush) Was kind of comical, actually. Both brushes were sitting there blowing air by themselves :)

Thanks for the tip, modelmaker66

Thanks for letting me know Greg.  I will have to hunt up some of that oil.