why my diaphragm pump airless paint sprayer doesn’t suck the paint ?

sometimes we got complaints from our clients that our diaphragm pump paint sprayer machine doens’t suck the material. let us explain to you. There’re 3 reason , and 3 step to solve this problem. It’s very easy.

1. If the sample is shipped by Air / Plane, or by DHL/TNT/FeDEX posting, we had poured out the hydraulic oil before shipment. (because the oil / liquid is not allowed to be loaded onto plane)

so you must pour  hydraulic oil  (about 0.8 Liter) into the pump,  The oil is 46# anti-wear hydraulic oil normally. but you can chose Good quality oil like Shell Tellus High Performance Hydraulic Oil 46# .   The oil is about 85-90% full, MUST not 100% full. please see below picture.

2. please use your finger or a pen  to push the spring nut inside the SUCTION VALVE (INLET VALVE)

This way is for make sure the Suction Valve Spring was not stuck after storage & transportation.

if you switch on the machine, you could feel the vibration of the Suction Valve Spring.

If the Suction Valve Spring is Vibrating, that means it’s ok for sucking the paint.

please see below picture.

3. Make sure the suction tube is tightly screwed on.

if the tube is too loose, the air will enter inside, then the paint couldn’t be sucked, or sucked very slowly, and also the pressure can’t reach 210bar or more.

4. If all above 3 steps are finished, but the paint still can’t be sucked, we’ll take the last step to exhaust the air inside the Oil Passing Way.

Because the machine will be shipped to your country through truck / container, during the long way transportation, the air maybe enter into the Oil Passing Way. so we must exhaust all the air out, and then the piston push the oil,and the oil could push the diaphragm for vibrating.

if there’s air inside, the oil can’t push the diaphragm any more, and the paint couldn’t be sucked of course.

How to exhaust the air inside the oil of airless sprayer?

it’s very easy, set the Prime Spray Valve in A. Prime position, and regulate the Pressure Control Valve to the Weakest (0 bar), and then switch on the machine, let it run for 30 seconds, then the air could be exhausted.

5. After the air exhausted, we could adjust the Pressure Regulator Valve clockwise to higher pressure.

There’s one small HEX screw to fix the out cover with inner pin. but sometimes this screw is not very tight, the result is: when you regulate the valve again and again, but the pressure is still same, dont’ go up.

If this happened, you need to push hard on the Regulator Valve and then turn it clockwise.

This will make sure the inner pin are turning accordingly.