12v water pump acting up

[modmidget]

Our motor home is just over a year old and has a Shurflo Model 4008-101-E65 water pump installed. A few days ago when I turned on the faucet at the kitchen sink we had good water pressure for a few seconds then the stream of water slowed way down. I could hear the water pump running and when I turned the faucet off it took 15 to 20 seconds (or more) for the pump to bring the water pressure up. Once the water pressure is up the pump does not run from time to time, so I'm pretty sure it's not losing pressure. We also lose water pressure at the bathroom basin and the shower.

[modmidget]

When the faucets are off the water pressure does not drop and the pump does not run. I checked all fittings and there are no leaks. I also replaced the 10" water filter in the WaterPur canister but that didn't help.

I've ran 3 or 4 gallons of water through the hot water tank (faucets) but there's still no change. The water pressure is so weak I don't get a spray out of the shower head, just a small trickle of water.

I've been trying to remember when this problem started. We were in South Dakota when we ran the fresh water tank dry. We drove to Sidney, Montana and stopped to see an old Air Force buddy that I hadn't seen in 46 years. We filled the water tank at his house but didn't use the pump until the next day. I think that's when the wife noticed the water pressure dropping off rapidly as she tried to wash some dishes.

[OnaQuest]

Are you sure that your water heater is full and the water heater tank bypass valve is closed? Turn on a galley hot water faucet and let it run even after it goes to a trickle. When the tank fills it should return to full pressure. If that bypass valve is open, you will find thaqt you have hot water for only a few seconds an then it will turn to cold.

[trickyvic3]

Check all your fittings and make sure they are good and tight. Sounds to me like you have a slight pressure leak somewhere. It is normal for the pressure to drop some when running off the water pump with a faucet on, but when not running water it should hold pressure and your pump shouldn't run. At least ours doesn't.