Why is my CAT pump sending morse code?

[Sequoia]

Normally, my 3 CAT pumps all sound pretty much the same when they are running. A recognizable hum.

Lately, my #1 CAT pump is making its usual noise, but also adding in a da-dadada-da--da-dadada or something like that. It sounds a little like when the customer squeezes and unsqueezes the trigger, but it's happening several times a second while the customer has the trigger squeezed. The pressure gauge is unmoved-- right around 1000 psi.

Any ideas?

 

[Randy]

From not being there and hearing he noise for myself, my guess would be a slight air leak in one of the low pressure seals or in the soap or wax supply lines. If it’s light metallic noise then it would have to be in the crank case.

 

[helpfuljames]

Randy has a good idea. Look for air leaks. I prefer the open hose into a bucket of water test to determine if it is an air leak. (short discharge hose directly from pump head and put the hose end under water to see if there is a stream of bubbles coming out.)

Also check your check valves (not the ones in the pump) for weak springs or worn elements. These seem to be the cause of many of the hard to diagnose problems.

The low pressure seals in the pump could be on the verge of failing. Air can be sucked in where water will not drip out.

Depending on the unloader or regulator you have this may have something to do with it. The problem sounds like a small air leak (cavitation) of some kind.

 

[pitzerwm]

In the past an operator sent me the wma file and I posted it and within an hour someone diagnosed it.

 

[I.B. Washincars]

Are you sure you don't just have a belt smacking the guard?

 

[Waxman]

That'd be cool; IB. Just bend the guard out a tad. GIT R DUN!

 

[Sequoia]

340

They are CAT 340 / direct drive.

 

[MEP001]

They are CAT 340 / direct drive.

Have you tried any of the suggestions offered to you? It's always nice to get some sort of update.

Can you upload some photos of the pump and plumbing?

 

[Sequoia]

Update

I had to leave the wash before doing any work on this particular issue-- so there is no update yet.

I will be back sometime this week both to tweak the new boiler as well as to address this issue. Plus I am meeting the guy that has my spare/rebuilt pump, just in case.

 

[phred113]

They are CAT 340 / direct drive.

Well, now you tell us.

Here are some ideas all related to that pump:
1) The high speed pump seals will wear faster due to speed. check those.
2) The velocity of water through the valves is greater, so then will be the washout.
3) The Lovejoy coupler may be worn.

Try a smaller tip and see if this gets worse. Try a larger tip and see if this gets better. It may be your regulator returning water (and air bubbles) to the inlet of the pump.

I agree with Randy and think it's air from somewhere.

 

[Randy]

If this is one of the pumps that froze last month when your car wash froze up freeze damage could be part of the problem.

 

[Sequoia]

Ideas

Thanks for the great suggestions. I will be back at the wash this weekend to implement these ideas. Hopefully all holds together until then.

Fortunately I didn't have any freeze damage inside the equipment room. During the 4 1/2 day power outage I left a propane burner running all night long-- and visited the wash each morning to see if it had turned into a smoking ruins. Fortunately nothing caught fire.

 

[Sequoia]

Resolution

Thank you for all the replies.

The culprit turned out to be weak/inadequate seals on the top of the CAT pump. The center one was poor, and I replaced on other one which looked a bit worn.