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Topic: Replaced coach water pump (Read 156 times) previous topic - next topic
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Replaced coach water pump
Replaced our ShurFlo 4008 water pump yesterday with the same model. I believe the pump replaced the original 5.7 model around 2006 by the original owner, so it has lasted 14 years before malfunctioning. The original symptom was an occasional additional burp or two awhile after turning off a faucet, but recently the noise had become odd sounding and repeated every few minutes. The new pump shuts off when water flow stops, with no burping.

I disassembled all parts of the old pump to see if it was repairable to keep as a spare. I found all parts intact and in good condition, but contaminated with mostly loose deposits. I cleaned everything, and re-lubed all o-rings. After initial re-assembly it no longer had the odd sound, but still burped every few seconds when tested. My test rig had the inlet hose pulling water from a bucket, and the outlet hose terminated by a valve stop, which would empty back into the bucket. With the valve closed to allow pressure in the outlet hose, power disconnected, I pulled the inlet hose out of the bucket and held it vertically. After a few moment, water slowly welled up out of the hose end. This means a check valve failure.

I pulled the pump assembly back apart, and found I could disassemble more parts of the pressure switch/check valve, and further cleaned off more deposits and lubed more o-rings inside. This time on re-assembly, the pump did not leak back and held pressure. So, I have a back-up pump again. BTW, these pumps are entirely mechanical - no electronics to fail.
2004 FL
2013 Honda Fit
 
Re: Replaced coach water pump
Reply #1 –
My 2003 is still using the venerable Whisper King, out of production for a few years now; the current pump is the second WK. When it dies, a 4008 stashed in a compartment, waits its turn. This conversion chart from Shurflo may be of use to select a replacement pump.

file:///C:/Users/Owner/Downloads/RV-Pump-Conversion-Chart%20(1).pdf

If one doesn't feel like a C&P, a link:

RV Water Delivery | Pentair
2003 TK has a new home