Bay running rough

[HCCW]

Ok you guys, I’m at my whits end. One of my self serve bays has a vibration and I have tried everything I can think of. It’s a belt drive set up running a Cat Pump 5CP2120W. I’ve been running 15 self serve bays for 25 years and they always run smooth. This bay started running a little rough a year ago and I figured the pump, which was old, was on its way out. I replaced it with a new pump in September and was shocked when it ran just as rough. It doesn’t affect the pressure in the bay, that’s as strong as ever. There is a tiny flutter in the guage every second or two but nothing a customer would be able to feel - only an owner as obsessed as me would hear it when they are in the equipment room and sit there and stare at the guage. It’s not overly rough in the equipment room and I don’t notice it sounding rough in the equipment room - where I notice it is out in the bay. The hose has a noticeable vibration and I can hear it in the metal soffit in the ceiling too. It’s like it’s sucking a teeny tiny bit of air somewhere but I cannot figure out where. Plus there is never a drip anywhere in the equipment room to suggest a crack in a fitting it something like that.
Here’s what I’ve tried so far with no luck:
New Cat pump.
New gun out in the bay.
New pulsation dampener hose.
Removed the wax, soap and weep lines and put plugs in them.
Hooked a hose up to the inlet and pressure fed it bypassing the tank.
New pressure regulator.
Checked the belts and they are great.
Swapped the hose going from the pump to the bay with a different bay and it followed the hose coming from the vibrating pump so I know it’s nothing in the lines in the attic or anything in the bay causing it.

I am ready to lose my sanity. The motor seems strong and smooth - I can’t imagine that’s the problem but I’m running out of ideas.
All I want for Christmas is to solve this.
Then I can die a happy girl.
Somebody put me out of my misery.

 

[Mr. Dude with a face]

Hi, I work with @HCCW, and figured I would add one thing we have tried to this thread. We heat our water for our High Pressure Soap, and that hot water runs through the pump. It seems to make no difference whether it is running hot water or not through the pump. Thanks all for and advice!

 

[Keno]

I saw you changed pulsation dampner hose, do you have a pulsation dampner also? We have had this exact scenario caused by a bad pulsation dampner, down to putting in a brand new pump and still having pulsating. Our pulsating was way worse than yours though and was effecting our pressure also.

 

[HCCW]

I saw you changed pulsation dampner hose, do you have a pulsation dampner also? We have had this exact scenario caused by a bad pulsation dampner, down to putting in a brand new pump and still having pulsating. Our pulsating was way worse than yours though and was effecting our pressure also.

We only have a pulsation hose on the self serve bays. Our automatics have big Cat 3535 pumps and they have the large black pulsation dampener. I wasn’t aware they make them for smaller pumps. I’ll have to get one and try it.

 

[Keno]

Not really needed on the smaller pumps, we just eliminate them when they go bad.

 

[HCCW]

Not really needed on the smaller pumps, we just eliminate them when they go bad.

I just reread your original reply and I think I didn’t read it right. Did you ever end up solving the problem? It sounds like yours was much worse than ours, but maybe they are having the same problem.

 

[Keno]

It was a bad pulsation dampener - we eliminated it and problem went away

 

[HCCW]

It was a bad pulsation dampener - we eliminated it and problem went away

Oh! Well I didn’t try taking it out of the equation all together. I’ll remove it and see if it smooths out.

 

[edredtop]

On the inlet side:
* did you reuse any old fittings that may have pinholes or cracks?
* do you have FO (foreign objects) in your water and do you screen/ filter your water before the intake to prevent sand, clear plastic, etc. that could be ingested and cause a valve to be obstructed?
and..
* did you reuse the same unloader?
* if you didn't replace the pulsation dampener, that's the very, very, very, first thing I'd do.

 

[Randy]

Try swapping the head off of another bay pump and see if the problem goes with the head. It sounds to me like you have a small leak somewhere.

 

[HCCW]

On the inlet side:
* did you reuse any old fittings that may have pinholes or cracks?
* do you have FO (foreign objects) in your water and do you screen/ filter your water before the intake to prevent sand, clear plastic, etc. that could be ingested and cause a valve to be obstructed?
and..
* did you reuse the same unloader?
* if you didn't replace the pulsation dampener, that's the very, very, very, first thing I'd do.

I did reuse all the old fittings. It possible one it cracked but I REALY wish if that were the case that it would at least have a teeny drip or something. I’m not sure where to begin when it comes to trying to sleuth it. Should I replace all the fittings?
Shouldn’t be any foreign objects in the water. It goes through several filtration systems and a final filter on the dole valve before entering the pump. Plus all the bays at this location run off of the same water line, so I would think some of the others would start running weird too?
On your third question I have a confession to make. I’m not sure what the unloader is. Even after 25 years. Is that the hose that runs from the top of the pump back into the bottom and circles the water around through the pump when the trigger isn’t being pulled? If it is, yes I reused that hose. I can try replacing it with a new one.
And on your final question - don’t laugh again but I’m not 100% positive that I know what the pulsation dampener is. I think it’s the hose coming out of the bottom of the pump that is a couple feet long and dead ends. I did try putting on a new one but it didn’t help.

 

[OurTown]

Pulsation dampener.

https://www.kleen-ritecorp.com/p-1518-kleen-rite-pulsation-dampener-10-gpm-600-3000-psi.aspx

 

[OurTown]

You might have a regulator instead of an unloader. They work differently but achieve the same goal.

https://www.kleen-ritecorp.com/c-1026-pump-regulators-and-unloaders.aspx

 

[Randy]

You don't necessarily have to use new fittings. I've got a couple of pails of fittings I reuse from time to time, I never use galvanized steel fittings on anything. I use Leak lock on the fittings when I have a problem. Can you post a couple of pictures of what your dealing with?