The check valve is leaking in your water pump. Might have debris in it. Start water pump for a few minutes and flush. Then try again and see if it fixed it. If not, you will have to take apart.
2011 Rockwood 8319SS with ProPride 3P hitch/GoodYear Marathons/TST TPMS 507
2008 F250 Lariat CC SB 6.8L V10 4.10 axle ratio (NITTO TERRA GRAPLER G2 LT275/65R20E)
Yamaha 3000iseb generator:Progressive Ind. EMS-HW30C : Eastern Ontario
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