# Graco 190es pressure problem



## Glosol (Apr 27, 2019)

My 190es is giving me troubles. The motor works, the pump works, the prime works, and it can still spray exterior paint. 

The problem is it runs constantly, and paint is getting past the primer valve. There is enough pressure at the gun to shoot paint, but it still leaks from the primer hose while shooting. There is more paint from the primer hose when the gun is not triggered. If I understand that valve correctly, it has a dual purpose of directing paint flow, and as a safety feature to regulate excessive pressure and dump that pressure out the primer hose. I replaced the primer valve with no change at all. 

My thought was the pressure transducer is bad, but there are no error codes on the control board led. Just to test if the control board was getting a signal from the transducer I unplugged it from the board and got the 3 flashes from the red led on the control board. After plugging that back in and cycling power, the code is gone. Does this sound like a transducer issue, or a control board problem?

Or something totally different?


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## AngieM (Apr 13, 2016)

Following 

Sent from my moto z3 using Tapatalk


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## CApainter (Jun 29, 2007)

The following is from the Graco 190es trouble shooting section: 
*Motor Runs and Pump Strokes:*
1. Prime Valve Open.
2. Paint supply.
3. Intake strainer clogged.
4. Suction tube leaking air.
5. Intake valve ball and piston ball
aren't seating properly.
6. Leaking around throat packing
nut which may indicate worn or
damaged packings.
7. Pump rod damaged.


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## Glosol (Apr 27, 2019)

The troubleshooting section is missing a big part of the picture. It still paints. The motor runs and pump strokes, and paint is being moved. Its enough pressure to run the gun, and the excessive pressure is being released past the prime valve. The pump is working great, check balls not stuck, good intake, 5 gallons of clean filtered paint, internal filters are new. 
The pump just keeps pumping, and when it reaches the relief pressure at the prime valve, it gets sent out the prime hose.


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## CApainter (Jun 29, 2007)

I'd look into replacing the pressure control assembly.


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## Glosol (Apr 27, 2019)

I failed to mention in my original post that this sprayer is the early version with electronic pressure control. Newer models have the mechanical pressure control assembly that I would be able to replace if faulty. 

On my electronic version, the pressure control is the electronic transducer. That plugs into the control board. To test the transducer I am supposed to use a known to be good transducer and swap them. If it works, the problem is solved.

Really? Is there no actual test for this part? 

I see it as either the transducer has failed, or the control board has. There are no error codes. The sprayer builds pressure and sprays, but will not turn off when pressure is reached, so the excess pressure releases from the primer hose. Turning the electronic pressure control knob has no effect on the pressure. It just pumps. It will turn the pump off if turned fully counter clockwise, but has no effect on pressure once the pump builds pressure.

I would rather not throw parts at it if they are not needed, so where should I start? Transducer or control board or ?


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## Fencer65 (Mar 13, 2021)

Glosol said:


> I failed to mention in my original post that this sprayer is the early version with electronic pressure control. Newer models have the mechanical pressure control assembly that I would be able to replace if faulty.
> 
> On my electronic version, the pressure control is the electronic transducer. That plugs into the control board. To test the transducer I am supposed to use a known to be good transducer and swap them. If it works, the problem is solved.
> 
> ...


Good day dear i have on my graco 795 same trouble ..the sprayer not stop pressing . Did you find the way to fix it ?


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## cocomonkeynuts (Apr 14, 2017)

Fencer65 said:


> Good day dear i have on my graco 795 same trouble ..the sprayer not stop pressing . Did you find the way to fix it ?





Glosol said:


> I failed to mention in my original post that this sprayer is the early version with electronic pressure control. Newer models have the mechanical pressure control assembly that I would be able to replace if faulty.
> 
> On my electronic version, the pressure control is the electronic transducer. That plugs into the control board. To test the transducer I am supposed to use a known to be good transducer and swap them. If it works, the problem is solved.
> 
> ...


Yes that is a bad transducer. It happens from not cleaning the machine correctly. Once you remove the existing transducer your very likely to find it caked in dried paint which end up damaging it. If you clean out the gunk it might start working for a short while but my experience is this is only a temporary fix as its already damaged.
Fix: Replace the transducer.

If its reaching enough pressure to blow the prime valve (aka emergency pressure valve) this probably needs to be replaced as well.


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