Pump troubles...

Just finished our first job of the season. It was a long winter here in Maryland. It's good to be working again. I unclogged a super dirty machine. Latex paint was left in it for two months. Ordered new hoses but ended up getting all but one cleared after several days of soaking in xylene. Took off the prime valve assembly and cleaned the housing as well. Repacked pump. For most of yesterday and today... pump worked fine but near the end... it started to struggle to pick up pressure after spraying. 1) Any thoughts on what to look for? 2) Can someone explain to me how a transducer works? What does it do? How will I know if it's going bad? I ask because I had to pull out dried paint from it with a small allen wrench.

Sounds like your pump might need a repack. Does the machine prime, but then won't build pressure? The transducer controls, when the pump will engage, to keep the pressure at your set rate.

Rcan wrote on Apr 16, 2015:Go to #2

Sounds like your pump might need a repack. Does the machine prime, but then won't build pressure? The transducer controls, when the pump will engage, to keep the pressure at your set rate.

It builds pressure. Drops while spraying and takes time to get back up. To the point to where I keep shaking hoses and stuff in order to "entice" it to build back up. I dont even know if that helps or anything but can't hurt. Lol. So if my machine is always pumping at 3000 PSI... that means the transducer is bad? Is this a part that I should have in my toolbox?

Try taking the transducer out and cleaning it. What series of machine do you have?

Rcan wrote on Apr 16, 2015:Go to #4

Try taking the transducer out and cleaning it. What series of machine do you have?

I did state in my first post that I repacked the pump (two days ago to be specific) and removed dried paint from inside the transducer... the little hole. How deep does it go and how would you clean it otherwise? I have the LineLazer IV 3900.

I would check the elbow where it threads onto the pump and the lower check ball. that elbow is notorious for plugging up after cleaning latex with a hot thinner.

Milt wrote on Apr 16, 2015:Go to #6

I would check the elbow where it threads onto the pump and the lower check ball. that elbow is notorious for plugging up after cleaning latex with a hot thinner.

Thank you. I probably would not have looked there intentionally. I definitely plan to disassemble it and take a look. I do plan to reinstall with the packings as is since they were only replaced two days ago. Tomorrow, I'm going to flush the machine completely and ensure all debris is gone before putting on the brand new hose/prime assembly as well as replace the prime valve. I do have new spray hoses. Should I put them on as well or just use what I have since I got it unclogged? Outside of a stuck clog... what is a good indicator of when to replace hoses anyway?

I've had hoses last three or more years, they only need changing when the inner lining wears out. You could have a stuck ball.

Sounds like the suction side is plugged. Clean it again. Clean everything from the pump back to the rock screen. When you are shaking the hose to get it to work more of the old paint is braking loose from inside the hose and causing it to plug. If it was not building pressure then I would suspect the ball is dirty and not sealing. Good luck

it does sound like a clog on the suction side. do what Milt suggests and recheck your suction hose and intake tube for trash that may come loose. if so, you will find it in the elbow or lower pump.

To be honest TruColors, knowing the machine had been sitting with dried latex paint inside for 2 months at least, I would not even attempt to unclog it! I would just discard the old length and replace it with a new one, regardless of the cost . There is always the possibility of dried flakes of paint still left inside to dislodge and clog up the pump and or tip, especially when using xylene to try to soften it. I want to be sure that when I need the striper to spray, it will spray reliably. 50 feet of hose is impossible to see inside to make sure it is perfectly clear for material passage. The other plumbing fittings are easier to check for dried debris and clean. I had removed and cleaned the transducer a few years back on my 3400 when it could not build pressure. Be very careful of the thin wires on it so as to not twist them at the transducer end. Turned out that the transducer did need to be replaced after speaking with a Graco service center rep. and then the prime/spray valve I had to clean as well. Worked like a charm after that.

Mike, Also hold the pick up hose straight and look through it. I have had plugs as long a 1 foot build in it. Looks like a long turd when they come out. We keep a 6 foot piece of drain line cable we can put in our drill and run through the hose or pickup tube. They can be really tough to get out. You probably don't need to break the pump down again, just the lower part where the check ball is. If it worked as long as you say after the repack I would bet the plug is in the suction side.

As Milt said check the gooseneck on the bottom of the pump. Another way to clean the suction hose, hold it straight, vice or helper etc....... a piece of 1/2" PVC pipe fits inside the hose.....run it back and forth and then blast it out with a water hose.

Sounds like a clog in one of your hoses.

All hoses replaced including pickup/prime hoses. Gun was also replaced. Filter housing was removed and the inside was powerwashed clean. I took this time to also replace the prime valve. Took apart the pump to clean out any trash. Did not find much. Reassembled and now it will not build pressure anymore. It just continually pumps. I can see it is trying to suck up the bucket of water but nothing is building pressure. Tomorrow, I will repack pump again despite it being newly packed only a few days ago. Important to note that I also moved all circuitry onto a new set of handlebars but everything looks like it was hooked up good. I also put on a new display board but it isn't displaying.

TruColors wrote on Apr 19, 2015:Go to #15

All hoses replaced including pickup/prime hoses. Gun was also replaced. Filter housing was removed and the inside was powerwashed clean. I took this time to also replace the prime valve. Took apart the pump to clean out any trash. Did not find much. Reassembled and now it will not build pressure anymore. It just continually pumps. I can see it is trying to suck up the bucket of water but nothing is building pressure. Tomorrow, I will repack pump again despite it being newly packed only a few days ago. Important to note that I also moved all circuitry onto a new set of handlebars but everything looks like it was hooked up good. I also put on a new display board but it isn't displaying.

is it sucking air from somewhere? Does your display boards have a good ground? just my 2 thoughts.

Chevron94 wrote on Apr 19, 2015:Go to #16

TruColors wrote on Apr 19, 2015:Go to #15

All hoses replaced including pickup/prime hoses. Gun was also replaced. Filter housing was removed and the inside was powerwashed clean. I took this time to also replace the prime valve. Took apart the pump to clean out any trash. Did not find much. Reassembled and now it will not build pressure anymore. It just continually pumps. I can see it is trying to suck up the bucket of water but nothing is building pressure. Tomorrow, I will repack pump again despite it being newly packed only a few days ago. Important to note that I also moved all circuitry onto a new set of handlebars but everything looks like it was hooked up good. I also put on a new display board but it isn't displaying.

is it sucking air from somewhere? Does your display boards have a good ground? just my 2 thoughts.

To be honest, everything looks good and tight. Checked a few times but I'll check again in the morning going over all the connections real slow to make sure I didn't miss any. As for the display board... I'm sure it has a bad ground. The new handlebars do not have threads where they're supposed to be. There's a hole but no threads. That confused me for sure but I'm going to have to tap them.