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Common Trouble Shooting When You Do Not Have Pressure or A Prime

If your sprayer lost pressure from one minute to the next, you probably have debris in one of the balls, known as inlet and outlet valves.

A quick removal of the inlet valve housing or lower ball will show if there is a paint chip or skin holding the ball in the open position. While you have the housing off look into the pump to see if anything is holding the upper ball open. This ball is harder to clean out and requires disassembly, but sometimes you can straighten a paperclip and work your way around the ball and try to clear the debris. 

If your sprayer loses pressure shortly after you press the trigger and take a long time to catch back up. It is also a problem with one of the balls. The quick way to determine which ball is to try the following procedure.

 Wait for the pump to come up to pressure while looking at the piston to see what stroke it stops in.

If the piston stops in the upstroke, the upper ball is okay, and the problem is in the lower ball. If the piston stops in the down stroke, the lower ball and the problem is with the upper ball.

On smaller pumps, the piston moves fast so you may have to repeat the procedure several times to make a clear determination.

If the pump stops in both strokes, the pump is working well look for a leak on the suction hose or tube.

If you simply cannot catch a prime, it is important to not simply wait while it is trying. Look for bubbles while submerging the prime tube in water or paint. If there are bubbles, but no prime, then there is a leak on the suction hose or tube. If you do not have bubbles, the first thing to do is hit the inlet valve housing with a wrench or hammer to free up the balls that are stuck due to improper cleaning or long storage. If hitting with a hammer does not help, take off the intake valve housing to check the lower ball. While it is off, take a thin Phillips screwdriver and poke into the pump to free or make sure the upper ball is free and without debris. Try to establish a prime again.

If still no prime, disconnect the hose coming off the back of the pump0 and try to prime again. If water comes out of that fitting, then that short hose is clogged and needs to be replaced. Hopefully, this provides some explanation of what is going on inside the pump of your sprayer.

Call me with any questions 1-800-400-5084 Greg Bittner


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