Cat 310/340 Problem Coming Up To Pressure

[MDrost1]

So, : ).

I have been noticing that a few of my CAT pumps are having issues coming up to pressure when I arrive at the wash first thing in the morning. Here is what I know. Perhaps someone can offer some advice.

1) The weep mizer has been on for a month or so. Could it be the cold weather? However, It was 50 degrees this morning, and the pump had a tough time coming to 1000psi.
2) After I hit the trigger gun a few times, it is fine for the rest of the day.
3) I thought it maybe a bad weep check(this checked fine) and the HP check valve(all good).
4) I thought it was isolated to two of my 5 bays, but this morning noticed it on another bay.

Thoughts and advice would be great!

Thanks,

Mike

 

[MEP001]

Unless you're weeping air, it's not the weep.

What does the pump sound like when it's coming up to pressure? If it's smooth and quiet, most likely either your regulators aren't working right (not likely) or there's a check valve that's not seating at first, which I assume you've eliminated as a possibility.

If it's rough, it's probably air in the pumps. Your low-pressure seals could be bad or weak, maybe when they get cold they contract and the pump sucks air until it warms up. You could have a bad check valve in a pump and a customer who comes in every night running tire or presoak for a long time so that air backs up through the supply lines to the pumps. I've actually had that happen, it was a tow truck.

 

[loewem]

Do you know when the seals and valves were replaced in your pumps? My wash had a lot of deferred maintenance and the pumps hadn't been maintained as well as they could have been. I've changed the seals and valves on three of the pumps and it has made a huge difference. The pumps worked before changing the seals and the valves, but after changing the seals and the valves I realized that they had not been working optimally. MEP's post about the low pressure seals allowing in air until the pump warms up makes sense to me.

 

[MDrost1]

Gents,

Thanks for the advice. Sorry for the slow response time. I swapped out my HP check and weep check. Hopefully that resolves the issue. I put a whole new seal kit in this one pump about 5 months ago. I am thinking it is a check and not the seals. Thanks again. Happy new year!

 

[MDrost1]

Well, it wasn't he check valves : ). Gonna swap the pump with a pump that has a new seal kit and see what happens. Thanks, guys.

 

[MDrost1]

Well, replaced the head with a newly resleeved head and seals. All good! Thanks!

 

[MDrost1]

Ok, well it's still doing it. I replaced the head with newly resleeved head. New seal kit and valves seem just fine. It was great for a week. Now it is doing it again. The only other check valves are the ones in the trough that are inline with the spot free rinse and tire cleaner/pre soak. Could it be those? What else could it be?

 

[1carwash1]

I had something similar happen. Occasionally, a customer would complain that the pump is not pumping. Then one day I saw air bubbles coming from the bottom of the rinse tank while the high pressure pump was running. As strange as it sounds, it appeared that the high pressure pump was actually pumping air from the wand backwards into the holding tank. Additionally, since one line provided water from the rinse tank to all the pumps, the air being pumped backwards would be sucked into other pumps in operation, resulting in multiple complaints that the pumps were not pumping. The solution ultimately was to replace all the input and output valves on the high pressure pumps. The pumps now come up to pressure quickly and no more complaints of "no water". In our case the pumps were General CW2040. Since the valve kits were not so expensive, we just decided to do all of them at the same time for good measure.

 

[MDrost1]

Interesting. I will look into that! I did replace the whole head assembly. Which includes the valves, seals etc. It is still doing the same thing. It worked great for a week, then the same thing began to happen, as it did with the old head assembly. Could something be wrong with the pump itself?

 

[loewem]

Is it isolated to one pump at this point?

 

[MDrost1]

Officially, yes : ).

 

[loewem]

That's good news. Can you switch a pump that you are not having problems with to this spot to see if it is the pump?

 

[Greg]

Hi MDrost1,
Not that this is the case but it sounds like the pump may be struggling to get water.
Check & replace the hose feeding water to the pump.
Don't know the age of your equipment but over time hoses can break down internally, restricting water flow to pump.

Good Luck - Happy to help !
Greg Thoennes
Arimitsu Pumps

 

[MEP001]

I doubt it's a water supply issue, because the supply won't start off restricted and then get better.

As mentioned, you could have air from a low-pressure function backing up through the high-pressure line and into the pump. If low-pressure, spot-free and high-pressure all come together at the same point near the boom, the check for this is quick. Run the bay for a few minutes on a low-pressure function, turn on spot-free until it runs clear, then switch quickly to high-pressure. If no air or low-pressure chemical comes out, it's not backing up. If it is, you'll see a significant shot of whatever low-pressure you were running.

 

[MDrost1]

MEP001,

Thank you very much for your time and assistance!