What SHURFLO writes about the bypass:
“NOTE: By-pass adjustment should only be performed by a professional techni- cian with proper gauges and equipment.
The by-pass is a spring loaded dia- phragm that opens up allowing water from the discharge side back to the inlet side. The by-pass is set to begin opening at about 40 psi and creating full by-pass at about 62 psi (lower pressure pumps will vary depending on the by-pass and pressure shut-off settings). The pres- sure switch on the pump is set to shut off at 55 psi. If the switch or by-pass
are adjusted too much, the by-pass and switch shut-off can overlap and THE PUMP WILL NOT SHUT OFF. Screwing the switch screw in clockwise will raise the shut-off pressure. Unscrew- ing the switch screw counterclockwise will lower the pump shut-off pressure. Screwing the by-pass screw in will raise the pressure at which the by-pass starts and raise the full by-pass pressure. Unscrewing the by-pass screw coun- terclockwise will lower the pressure at which by-pass starts and lower the full by-pass pressure.
WARNING: If full by-pass is reached before the shut-off setting, the pump will not shut off. Full by-pass pressure setting should be at least 10 psi higher than pump shut off pressure.”
The bypass will not help solve the problems associated with thermal expansion.
2016 Rockwood Windjammer 3029W Diamond
2015 Chevy 3500HD LTZ 6.0 Crew Cab 4x4 Long Bed 4.10:1 SRW