If discharge pressure is lower than expected with full throttle, what steps should you take?

• A. Increase throttle further
• B. Inspect for leaks, closed valves, kinks, air in lines, inadequate water supply, or pump RPM issues
• C. Replace the pump
• D. Stop pumping and reassess after cooldown

Answer: (B)

When discharge pressure is lower than expected even with the throttle wide open, the problem usually lies in the system delivering the water rather than how much you’re asking the pump to push. A systematic check of the entire flow path is the right move: look for leaks in suction or discharge lines, valves that aren’t fully open, any kinks or restrictions in hoses, air trapped in the lines, an inadequate water supply, or the pump not reaching the proper RPM. Each of these factors can keep pressure down even at full throttle. If you find and fix leaks, open closed valves, remove kinks, purge air, ensure a sufficient water source, and correct RPM, the pump should be able to reach the expected discharge pressure. Simply cranking up the throttle won’t fix these issues and can risk damage or unsafe operation. Replacing the pump is only warranted if there’s actual internal failure discovered during diagnosis. Stopping and reassessing after cooldown isn’t necessary when you can identify and correct the root causes now.