Shure-flo pumps go to around 55 Lbs pressure,
One hose clamp at each end of a hose is normal.
Drain and refill the water heater so air gap will compress
the added pressure from heating the water.
If hose was too short, and clamps never retightened in 18 years
could sure cause the problem. All sounds normal to me.
Rich
'01 31' Rexall Vision, Generac 5.5k, 1000 watt Honda, PD 9245 conv, 300 watts Solar, 150 watt inv, 2 Cos 6v batts, ammeters, led voltmeters all over the place, KD/sat, 2 Oly Cat heaters w/ ox, and towing a 2012 Liberty, Lowe bass boat, or a Kawi Mule.