I have recently bought one of these to replace a bad water pump in a 2007 Sunline. It worked well. It is not an exact match to your old one, it is an upgraded model but if it can fit in the space which odds are high it will, it does work well. https://www.amazon.com/SHURFLO-4008-...gateway&sr=8-1
And yes, when the water pumps if they are the standard ones Sunline installed, have an internal pressure switch as part of the pump to shut it off when the pressure builds to the pump set point.
If yours will not shut off, does it build pressure? If there is a leak in the system and it is large enough, the pump will not shut off.
Hope this helps
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC
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