Pumped Up Or Not

[Rusty Bear]

I have installed my 3rd latest and greatest high pressure Shurflo water pump ( Shurflo was kind enough to replace the last 2 replacements) in my coach in the last year and a half, all with unsatisfactory results. My latest pump is now pulsating when I use it. The water pressure comes on as it should only to fade to a slow flow then back to full pressure. If I turn the water on slowly and advance the amount of flow slowly it will obtain full pressure and maintain the pressure while in use. This pump has an adjustable flow screw in the center of the end plate and I am wondering if anyone knows if this adjustment would fix the problem and how it should be adjusted.

Jim & Viv

[Rusty Bear]

I have installed my 3rd latest and greatest high pressure Shurflo water pump ( Shurflo was kind enough to replace the last 2 replacements) in my coach in the last year and a half, all with unsatisfactory results. My latest pump is now pulsating when I use it. The water pressure comes on as it should only to fade to a slow flow then back to full pressure. If I turn the water on slowly and advance the amount of flow slowly it will obtain full pressure and maintain the pressure while in use. This pump has an adjustable flow screw in the center of the end plate and I am wondering if anyone knows if this adjustment would fix the problem and how it should be adjusted.

Jim & Viv

[Cruzer]

Yes, you can turn the screw in but it doesn't take much. Give it 1/4 turn and test it. If it needs more, try it again. 2 turns would probably be way too much total adjustment so do it in small steps. Keep track of how many turns in case you have to back out to your original settings.

[gjstacy]

Hi Jim & Viv,

When we encountered this problem with our latest Shurflo, which also has the screw adjustment, we learned that we needed to provide more electricity to the pump. Once we added a second electrical wire to the pump, we have had no further pulsation problems. It still starts slow, but once it picks up pressure, it stays steady.

John just remarked that he thinks we also added a grounding wire.

See you next month!!

Gail

[Mike & Nancy]

Hi Gail.....Could you explain in more detail about more ELECTRICITY to Shurflo water pump.

See ya in Yuciapa

[gjstacy]

Hey Mike,

Our guy ran a dedicated wire from the batteries to the water pump to provide the extra boost needed. This wire is in addition to the standard wire feeding the pump.

In Yucaipa, you guys can all put your heads in our basement to see how it is wired. That's probably the best way to understand the setup. Neither John nor I are savvy about wiring, so would have a hard time explaining much more.

See you there!

[Mike & Nancy]

Gail.....So your water pump must always be "on" if its wired directly to battery? I will look at your pump wiring in Yuciapa.....

[gjstacy]

Well, that's a good point, Mike. But, it doesn't kick on unless we have the switch turned to "on", so I'm not sure how this works. Hopefully, a look at the setup will help you understand how and why it works.

[Jim A]

I would guess they added a relay. The normal circuit (and additional switches if desired) controls the relay, which will allow a higher current to the pump. Vegabondman mentioned that to me when I bought my SeeLevel gauge from him.

I never found the power to the pump lacking, so no wiring change needed. (And we run off the pump all the time, not the city water.) Just the mechanical reliability of the pump.

[gjstacy]

Jim A, that's probably a better way to go...a relay, that is. Knowing the guy that did this work for us, and that he is more of a mechanic than an electrician, he probably jerry-rigged it for us. However, I do believe it was ShurFlo that suggested we supply more power to the pump, as these new ones have been problematic for nearly everyone judging from previous threads. I know Dale Gerstel added an accumulator tank to his, and that works, too.

See you all in a few weeks.

[dgerstel]

I added a larger wire from the fuse block behind the holding tanks, upgraded the ground, added a relay and added the accumulator tank. The wiring, was done to meet Shurflo's requirements for these new pumps. The stock wiring is very long, with some very small wires at the pump switch on the tank monitor panel.

[gjstacy]

Dale, I should have known you did a lot more than just add the tank!

[Rusty Bear]

Thanks to All

I guess I will wait to talk to you all at the rally and maybe take a look at what was done to Gail & John's coach to resolve the problem.

We are away and using the coach until next week. The water pressure here in Big Bear is minimal at best, so we have been using the pump along with whatever water pressure is available most of the time.

My office is close to Sureflo so next week I will take the time to drop by and check out the extra wire theory and how it should be wired. I think the extra wire installed in Gail & John's coach must use a relay and is triggered when the pump is used.

Only a layman's guess.

See you all in Yuciapa
Jim & Viv

[Rusty Bear]

I finally had time to take my pump to Sur-flo.

Here is what I learned. The 5.7 model that I have works fine with the existing wiring to the pump. The problem was in the adjustment screw in the center of the base. Sur-flo put the pump on their test equipment and calibrated the set screw and the pump works as it should now.

If any one else is having this problem and can not get to Sur-flo, try adjusting the set screw no more than 1 ¾ turns clockwise.

The electronics in this model is not designed to work with accumulators according to their service center representative.

Jim & Viv