Paint leaks from fuji hvlp air diffuser

U

usatu

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Joined
Oct 20, 2016
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Hi-experts,

While I am still figuring out my finish problems, I keep getting paint drips from one side of air diffuser and one side of air cap also got paint on it. Through manual, I thought it is caused by needle packing nut. Apparently that's not the cause. Please advise if you know the solution.

Another issue is I probably loose the needle packing nut too much and now got a leak in the nut when I pull the trigger. I remembered that needle packing nut's gaps positioned horizontally. If you have the T series gun, can you please help me look?

Thank you so much!
 
Tighten the packing nut one quarter turn at a time until the leak stops. Make sure the needle moves freely.

Check the back of the air cap, there may be a little paint/finish on it. Make sure you put the air diffuser back in the gun last time you cleaned it.

Tom
 
Will try tomorrow. I cleaned everything and put it back and still got leaks before I touched needle packing nut. According to manual, LEAKAGE FROM THE NOZZLE
This occurs when the Needle Packing Nut is too tight compressing
the Needle Packing #12 tightly around the Needle.
But I found is big leaks come from the diffuser holes and a tiny bead of paint on nozzle and needle tip after pulling the trigger. So I am not sure manual tells the solution on that.

tjbnwi said:
Tighten the packing nut one quarter turn at a time until the leak stops. Make sure the needle moves freely.

Check the back of the air cap, there may be a little paint/finish on it. Make sure you put the air diffuser back in the gun last time you cleaned it.

Tom
Click to expand...
 
Packing nuts don't need to be removed for normal cleaning only if replacing it.

A paint leaking from the air diffuser means that your nozzle is leaking from its threads to the diffuser.
 
wptski said:
Packing nuts don't need to be removed for normal cleaning only if replacing it.

A paint leaking from the air diffuser means that your nozzle is leaking from its threads to the diffuser.
Click to expand...

Does that mean tighten the nozzle more?
 
Loosen the nozzle and reseat it.

Paint moves from the cup, into the fluid chamber and out the nozzle into the air stream. If everything is correct no fluid ever enters the air chamber in the gun body. As Bill stated, the fluid has to be coming from the nozzle to body area.

Check the clock on the diffuser, make sure it's set on the pin properly.

Tom
 
Tried a different nozzle and still get the same problem. But if I remove air diffuser and put nozzle on , no water leaks. So I am not sure whether it is the plastic ring on air diffuser going bad. I also can hear air leaking sound from the cup.

wptski said:
tjbnwi said:
There is no seal nozzle to buy. It is a seat fit.

Tom
Click to expand...
Yes, it relies on its threads and a slight shoulder to butt up against.
Click to expand...
 
usatu said:
Tried a different nozzle and still get the same problem. But if I remove air diffuser and put nozzle on , no water leaks. So I am not sure whether it is the plastic ring on air diffuser going bad. I also can hear air leaking sound from the cup.
Click to expand...
I don't have a T-70 to play along here but it seems that the air diffuser is part of your air path to the air cap not the product being sprayed "unless" it's stopping the nozzle from sitting properly and therefore leaking.  The nozzle has to be removed before the diffuser and divider as the video shows.

Maybe Tom or Tim can answer as they both have a T-70?   
 
usatu said:
Tried a different nozzle and still get the same problem. But if I remove air diffuser and put nozzle on , no water leaks. So I am not sure whether it is the plastic ring on air diffuser going bad. I also can hear air leaking sound from the cup.
Click to expand...

I still need pictures of your gun and cup and those areas that you think are leaking.
Tim
 
Sorry，only have one with water dripping. Thanks
 

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From the picture I see a couple of things.
First, replace the check valve tube. The inside looks dirty. Both tubes and valve.
Second, you need to tighten the fluid nozzle as tight as you can. This should prevent any leakage that you are getting.
Thirdly, you may want to replace the diffuser seal.
Fourthly, make sure when you tighten the metal collar as well.

Cheers,
JC

 
JCLP said:
From the picture I see a couple of things.
First, replace the check valve tube. The inside looks dirty. Both tubes and valve.
Second, you need to tighten the fluid nozzle as tight as you can. This should prevent any leakage that you are getting.
Thirdly, you may want to replace the diffuser seal.
Fourthly, make sure when you tighten the metal collar as well.

Cheers,
JC
Click to expand...
Yeah, looks like water inside the tube or is that just on the outside?  Is the hole in the cup baffle positioned for the angle your using it?  If that's wrong plus a bad check valve, you's get the product or water in this case in your air passage ways.
 
usatu said:
Sorry，only have one with water dripping. Thanks
Click to expand...

Thanks.
Can you take a picture of the inside of the gun where the nozzle threads into the gun and the individual parts.
It appears the leak is coming from the fluid nozzle and it needs to be tightened, but it may be that the thread is clogged with finish and preventing a proper seal. Don't over tighten the nozzle.
It could be the check valve is leaking, but usually that creates intermitment problems not a consistent stream.
Tim
 
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