ShurFlo 4008 series Check Valve Replacement

[charliem]

To all my fellow CL owners suffering from check valve failure on ShurFlo 4008 series pumps. Symptoms are frequent pump cycling with no apparent leaks and/or city water backfilling the FW tank. The steps are:

   
• Order ShurFlo check valve replacement kit P/N 94-800-03
• Remove three screws
• Remove and replace three plastic parts and one spring
• Reassemble and reinstall three screws
• Check for leaks

Ten minutes if you're slow. I didn't even have to remove the pump. Simple fix when the standard "recycle to remove sand" procedure doesn't work.

[dlb53151]

Hi Charlie - when you say frequent pump cycling I assume you mean the pump is making a noise even when water is not turned on?


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[charliem]

Correct. With city water disconnected or turned off and the pump switch turned on the pump should run to pressurize the system and shut off. If you don't use any water the pressure should remain. If the pump runs for short bursts it is replacing the lost pressure due to a leak. The recycle time can be anywhere from a few 10s of minutes to a few hours depending on the size of the leak. If you can't find any water leaking on the floor or dripping from under the camper it's probably leaking back into the FW tank. That means the check valve in the pump is not holding. Another symptom is the FW tank filling and overflowing when city water is connected.  That will get your attention. The common fix is to cycle the pump several times to try to dislodge sand or dirt in the check valve but the valve does occasionally really fail. Fortunately the repair is simple and fast.