Hello all- We have a 6 year old travel trailer and over the past few years we have had an annoying issue with the water pump that I am getting really frustrated with now. If the unit sits for a period of time with an empty tank, or if we camp with hookups in between outings where we use the tank, I can't seem to get the pump to prime on its own the next time we try to use it. It will turn on with a quiet hum and never do anything. When this happened in the past I used to be able to put my finger or something else in the outside tank vent hole for a minute and then release and that would work but I have not been able to make it work. The only thing I can do, and have been doing, is to disconnect the inlet hose from the pump, put a funnel directly into the pump and pour water in and reconnect the hose. That seems to cause a prime that then works as long as we keep the tank filled and keep using it.Any idea why the pump no longer primes on its own the way it should? Thanks!

For about $70 you can buy a new Shurflo pump on Amazon and be done with your issue,,,just saying,,,

Could be the diaphragm, could be the check valve, could be the seals… Buy a rebuild kit on line and hope that fixes it. Or you can spend about $15 more and get a whole new pump that will be good to go for about another 6 years.

Since the issue started a couple years ago, I will say a 4 year old pump should not be worn out, needing replacement parts. It is more likely sucking air from a source, such as a loose fitting or crack between tank and pump.If no issue found, then I'd try a new pump. They are cheap, compared to the aggravation of manual priming. Most pumps self prime easily, and certainly prime with a faucet cracked open a bit.Jerry

ditto of MFL. Especially his last sentence about opening a facet.

If you have ever taken one of these pumps apart you will see that the diaphragm is a very thin piece of material subject to age & dry rot. Kits are available for some pumps. Might as well get a new pump. Your time is worth more than messing with the thing past making sure there are no air leaks in connections on the low pressure side of the pump.Just went down the failed pump road. Leaking gasket on the pump. I carry a new spare so the change out only took a few minutes. Since then I have hopefully repaired the old pump by replacing the gasket & it now sits ready to go if needed.

Priming the water pump | Good Sam Community

IB853347201
Nomad
May 14, 2023
For about $70 you can buy a new Shurflo pump on Amazon and be done with your issue,,,just saying,,,
nickthehunter
Nomad II
May 14, 2023
Could be the diaphragm, could be the check valve, could be the seals… Buy a rebuild kit on line and hope that fixes it. Or you can spend about $15 more and get a whole new pump that will be good to go for about another 6 years.
MFL
Nomad II
May 14, 2023
Since the issue started a couple years ago, I will say a 4 year old pump should not be worn out, needing replacement parts. It is more likely sucking air from a source, such as a loose fitting or crack between tank and pump.

If no issue found, then I'd try a new pump. They are cheap, compared to the aggravation of manual priming. Most pumps self prime easily, and certainly prime with a faucet cracked open a bit.

Jerry
prichardson
Explorer
May 14, 2023
ditto of MFL. Especially his last sentence about opening a facet.
Veebyes
Explorer II
May 14, 2023
If you have ever taken one of these pumps apart you will see that the diaphragm is a very thin piece of material subject to age & dry rot. Kits are available for some pumps. Might as well get a new pump. Your time is worth more than messing with the thing past making sure there are no air leaks in connections on the low pressure side of the pump.

Just went down the failed pump road. Leaking gasket on the pump. I carry a new spare so the change out only took a few minutes. Since then I have hopefully repaired the old pump by replacing the gasket & it now sits ready to go if needed.
kfp673
Explorer II
May 14, 2023
Thanks all. I have checked to make sure no fittings are obviously loose or have any obvious issues which I can't find. Everything is snug. Must be an air leak somewhere but maybe I'll just try a new pump. Won't be happy if it behaves the same but if they are in the $70 range it's probably worth a try. Thanks!
2112
Explorer II
May 14, 2023
I have a similar issue after I drained the lines for winter. I turn on the bathroom cold faucet (closest faucet to the pump) and problem solved.

I turn the faucet off once all the air sputters out.
LouLawrence
Explorer
May 14, 2023
kfp673 wrote:
The only thing I can do, and have been doing, is to disconnect the inlet hose from the pump, put a funnel directly into the pump and pour water in and reconnect the hose. That seems to cause a prime that then works as long as we keep the tank filled and keep using it.

Any idea why the pump no longer primes on its own the way it should? Thanks!

What I don't understand is how you can disconnect the input line and not have water flowing everywhere. That line should be full of water and supply lots more water to your pump than a funnel could provide. Is the pump above the tank?
wa8yxm
Explorer III
May 14, 2023
I agree with the new pump only that price seems high (But then it's been some years since I replaced one.

One make sure fresh tank is FULL

Two.. open faucets. Kitchen and bath before turning on pump.

3 Insect lines for valves and holes.
Veebyes
Explorer II
May 14, 2023
Disconnect at the output side of the pump. Hold your thumb over the pump outlet & turn it on. Pressure? Yes? Suction is fine. No? No suction. Trace backwards. Pump itself plus fittings. It does not take much for an air leak on the low pressure side.

Forum Discussion

Priming the water pump

About RV Tips & Tricks

Related Content

Water Pump won’t Prime

Diesel fuel filter priming pump

Cummins Water Pump

water pump replacement

Water pump