Cat 30 pump pressure dropped to zero

[stacker2005]

Hello everyone, I've been following this forum for a few months. The car wash I work at has a Cat 30 pump (direct drive) that recently quit working. Here's what it's doing:

When I activate the test switch, sometimes it will come up to pressure just fine, but more often now, it stays at zero pressure on the manifold. I verify by checking the gun and indeed, there is no pressure.

When pressure does come up, about half the time, it will fluctuate greatly between about 400 PSI and 1200 PSI on the manifold gauge. The other half the time, the pump works exactly right, but as I said, it's working right less and less now.

I don't have any manuals or literature for this car wash, so I'm hoping the forum experts here can steer me in the right direction about things to check next. I'm not experienced with car washes, but I've been a mechanic for over 25 years, so I'm hoping that helps.

Thank you again for any ideas or help!

Andy

 

[stacker2005]

Something else I wanted to add. About a week before the pump started acting up, I changed a leaking valve in the back of the intake reservoir for the pump water supply. It looks to me like a mixing valve, it's pinkish and has cold and hot water lines connected. The thing is, now the water is pretty hot in the reservoir, I wonder if I'm baking the pump with too hot of water? I can test that theory by shutting down the hot side, but I still don't know what the valve does that I changed and I don't see any way of adjusting the water temp on that valve.

Also, it's been well below freezing for 2 weeks. The equipment room where the pumps are is nice and warm. Everything else with the car wash seems to be working ok. Bays 1,2 and Auto are all good, it's just this bay 3 pump. Thank you again for any help!

 

[I.B. Washincars]

It sounds like it is not getting water. Hook an unrestricted hose directly to the pump inlet and see if it works then. A garden hose, elevated bucket, tank or anything that will flood the inlet should let you know if the pump is not getting water. Once you rule that in or out you should have an idea where to start looking.

 

[2Biz]

A picture of your pump and plumbing would be nice...

Could the coupling between the pump and motor be slipping since its direct drive? (causing the pressure issue)

It could be lots of things like I.B. posted...Make sure the pump is actually turning and the pump is getting water then go from there. It could also be a failing regulator...

 

[2Biz]

Also, from a Cat 310 manual...A 310 will operate up to 130° water temperature and up to 160° water temperature if it has the right seals to take the higher temps. If your water temperature is too hot, it has to be tempered with a mixing valve or turn down the temperature of your hot water heater. But knowing the exact temperature will help. An Infrared Thermometer is a nice tool to have at the wash...

http://www.amazon.com/gp/product/B002YE3FS4/ref=oh_details_o01_s00_i00?ie=UTF8&psc=1

 

[stacker2005]

Really appreciate the responses!

It sounds like it is not getting water. Hook an unrestricted hose directly to the pump inlet and see if it works then. A garden hose, elevated bucket, tank or anything that will flood the inlet should let you know if the pump is not getting water. Once you rule that in or out you should have an idea where to start looking.

Thank you for the replies! It's great to have a place where I can look for help, especially since there are no maintenance manuals or anything with this car wash. I'll try the inlet water idea today to see if it changes anything.

I was thinking an issue with the coupling as well, but I'm not even sure how the pump is coupled to the motor. In aviation, we usually had things connected to engines via shearable shafts, which the idea was that if there was friction or a siezed bearing, the shaft would shear instead of eating a million dollar plus gearbox. I'm pretty sure that when I charge it and the pressure is zero, the only thing operating is the electric motor. I listen and feel for the pump running too, but I don't think it is.

I'm going to see if I can see anything in the hole at the mating area, but of course it's the pump that's the most difficult to get to, LOL!

I wish I had diagrams, if I have time, I'll draw it out and post it here, but I only do the car wash part time, the rest of the time I'm in the Ace store that owns the car wash. I will try to include pics if I can when I have questions on here. I don't want to waste people's time, so if I can make it easier, I'm all for that!

 

[MEP001]

If the pump loses prime, it can be a chore to get it primed again. Is this on a Futura stand with the individual tank for each pump? I used to have to work on one and the only way to get it primed was to remove a top valve cap and pulse the pump on and off until some water would flow. The whole mess was eventually replaced with one large hot water tank which really helped with maintenance issues.

 

[2Biz]

I was thinking an issue with the coupling as well, but I'm not even sure how the pump is coupled to the motor. In aviation, we usually had things connected to engines via shearable shafts, which the idea was that if there was friction or a siezed bearing, the shaft would shear instead of eating a million dollar plus gearbox. I'm pretty sure that when I charge it and the pressure is zero, the only thing operating is the electric motor. I listen and feel for the pump running too, but I don't think it is.

I've never had one apart or saw one up close. But since there is a housing between the motor and pump, I would think the coupler was the finger type. Unless there is an access hole to tighten up coupler bolts....But I wouldn't think it would be a rigid connection. That's why I bet on the finger type coupler. I don't think it would be too hard to take the motor off and check the coupler....What is there, 4 bolts?

 

[MEP001]

I was thinking an issue with the coupling as well, but I'm not even sure how the pump is coupled to the motor. In aviation, we usually had things connected to engines via shearable shafts, which the idea was that if there was friction or a siezed bearing, the shaft would shear instead of eating a million dollar plus gearbox. I'm pretty sure that when I charge it and the pressure is zero, the only thing operating is the electric motor. I listen and feel for the pump running too, but I don't think it is.

There's definitely nothing that sophisticated to it. Worst-case, the key is either worn away or sheared, but you'd never get pressure if that happened. It may sound like the pump is not running, but they just don't make any sound when there's no pressure.

I've never had one apart or saw one up close. But since there is a housing between the motor and pump, I would think the coupler was the finger type. Unless there is an access hole to tighten up coupler bolts....But I wouldn't think it would be a rigid connection. That's why I bet on the finger type coupler. I don't think it would be too hard to take the motor off and check the coupler....What is there, 4 bolts?

There are two coupler types for them, one that uses the Lovejoy-type coupler and one with a hollow-shaft motor for the pump shaft to fit into.

 

[Erik_Catpumps]

Stacker2005
Here is a Data Sheet on your Model 30
http://www.catpumps.com/products/pdfs/30.pdf
and Service Manual
http://www.catpumps.com/products/pdfs/30.pdf
Please let me know if you need more help.
Thanks
Erik
Cat Pump tech

 

[Stuart]

........ it's pinkish and has cold and hot water lines connected. QUOTE]

This sounds like the doyle valve. I have had a few issues with the diaphragms sticking on mine. I replaced the diaphragms and the problem left. Make sure the water supply is not too hot as I believe this may have been my problem. I plan on replacing diaphragms 1x a year to fix this. This is all based on enough water supply to the valves.

A problem at another location was my inlet check valve was sticking closed or part closed. Replaced it and all is good. Hope this may help. good luck

 

[stacker2005]

 

[stacker2005]

https://plus.google.com/photos/1075...ms/5958924564005506193?authkey=CJnF97HDhPaHeQ

Thank you for all the help again. I've got some updates if anyone has other ideas.

I tried to post some pics of the pump setup there, but I don't know if it worked. Also, there's a link here: https://plus.google.com/photos/1075...ms/5958924564005506193?authkey=CJnF97HDhPaHeQ

I changed the pink valve, as Stuart above said, it's called a 'Dole Dual Inlet Solenoid Valve', or that's what Kleenrite calls it. When I went to check my inlet supply, I noticed that if I turned off the hot water supply at the wall manifold while the pump was running, the water supply into the reservoir shut off completely. So there was no cold water at all mixing into the reservoir. What I did next was tried switching the lines. That has worked. Now the reservoir is cool water, not very hot water, like before. Both of my other pumps that work well have cold water running in their reservoirs, so I think that's how it's supposed to be. But the lines are backwards of what they are for the other two pump reservoirs. Strange.

Now the pump fires up every time. That's good, but it's not running real hot.

When I fire it up, it climbs a little slowly at first, but then it stables out at 1200. If it hasn't been ran in a few hours, it's pretty slow to get up to pressure. Then when I squeeze the wand, the pressure drops to 800. It is a very noticeable drop compared to how it has been in the past.

Also, the line feels like there's a jackhammer in it. I don't hear it and the pump doesn't sound bad, but you can sure feel it! I hope what we have is something not too difficult because someone also drove into my auto door and I have many issues with that right now. It took me 5 hours today just to get the damned thing down, but my auto bay is broken right now because of the door. We only have 4 bays and 2 of them are down right now. I love winter!

 

[MEP001]

Sounds like a problem with the pump.

 

[stacker2005]

I have a definite feed problem that I don't understand. It all goes back to that stupid pink solenoid valve on the backside of the reservoir. See pics above. The feed hot and cold water hoses connect to the mixer solenoid valve (Dole Valve) on the backside. Inside the reservoir, there is a float that screws into the solenoid. The other day I had ran the crap out of that pump with zero problems, so I had reopened it. The very first customer that came through, I heard the pump drop off and verified zero pressure on the manifold. I also noticed that the reservoir was nearly empty. I manually moved the float and there was no water being released by the Dole valve at all!!! It seems this valve has a mind of it's own and I'm having a hard time figuring out this problem when I don't even really understand how this valve works. Is there a better solenoid valve I can put on the backside of my pump reservoirs?

 

[MEP001]

I doubt it's the solenoid since you had the same problem with the old one. It's most likely the wiring that energizes the coils. The reason it has two inlets is to switch between hot and cold, and somewhere in the wiring is a relay that makes it switch, probably on the rinse circuit. Do you have a voltmeter?

 

[2Biz]

Like Mep said, the Dole Valve Switches between hot and cold water depending on the selection in the bay. If you could give us more detail, it might be easier to diagnose. Like how many functions are cold, how many hot. If more than one function is either hot or cold, then there has to be a relay between the two functions to keep from back feeding the circuit not selected. So my guess is as Mep says, sounds like a relay not picking up. Maybe if you ran the bay and tested each function, cold and hot....You might find the culpret a lot faster.

Let me give you an example....If soap and wax are hot water, then the dole valve will switch to let hot water in the float tank when either soap or wax is selected. When you select rinse, the hot valve closes and opens the cold water inlet on the Dole....Make sense. If you have hot wax and soap, there has to be a relay controlling that circuit. If there wasn't a relay when soap was selected, it would backfeed and open the wax solenoid at the same time. So that is why there would be a relay in the circuit, to keep that from happening. If you have more than one cold water function, then there would be a relay on the cold circuit...Like Mep said. Knowing more about your system helps...

 

[stacker2005]

The old Dole valve was only leaking, that's what I changed it. I was almost tempted to put it back on, but it was pretty old. I gave up and we had a guy come out today. He read out the relays that MEP001 and 2Biz were talking about. I couldn't stay with him and all I know is that he found a wiring issue and we've had the bay open since with no problems. I'm glad that I understand what the Dole valve does now...it will help to troubleshoot future problems. Thanks again for the great info!

 

[stacker2005]

I have an update to this problem. It went away for a time, but now it's back. The problem only happens with high pressure soap. As in, when you select high pressure soap, the Dole Valve does not allow mixed water to enter the reservoir and it starves the pump. Select any other wash cycle and it's fine. Also, I think the HP Soap check valve may be bad, I've noticed twice that a small amount of soap enters the reservoir and it makes the whole reservoir soapy. Probably not the greatest for the pump, I'm guessing.

My thought is that I should be getting a 24V signal to the Dole Valve, but I'm guessing the voltage is not there. So I need to figure out what tells the dole valve to open when high pressure soap cycle is selected. As always, I appreciate any help I can get on this forum!

 

[Stuart]

Check to be sure the hot water is not too hot. This could cause many problems. The diaphragm in the valve does not work well with too hot water. No more than 115 degree at most.
Check upline on the lines to see if there may be an area of obstruction in the line i.e. a check valve not opening fully or a sol-valve. Checking for power to the dole valve is easy to verify but this does not sound like the problem to me but stranger things have happened. ( For a long time we thought we were built over a cemetery in '86. For years we had one certain bay always having problems-water, elect, pump, switches. had everybody and their dog out to check it and could never find a problem. Fixed itself about 6 years ago with no rhyme or reason)
Turn on the soap and when the pump starts starving, without turning the bay meter off, go into the ER and turn pump off at breaker and then start troubleshooting from the tank back. Check flow of water, power to sol-valve. Just because you may have pwr to valve, the valve itself could still be the culprit. Then work back through the line to find the problem.

As for the soap in the tank- check the sol-valve for soap. There may be something in the enclosing tube which may prevent it from fully closing or the rubber tip is impressed too much. Might exchange the piston. That's all I have for now- Good luck.