Cat 3535 Valve Springs Keep Breaking

[toddmullens]

I have a bunch of old water wizards and seem to keep breaking valve springs on the cat 3535 pump. Anybody have any idea what could be causing this? Cat says it cavitation or excessive turbulence, put I am not sure where to look to find the cause of excessive turbulence. I am fairly confident its not from cavitation. I have no leaks on the inlet of the pump and have replaced the tubing for the wax and soap to hose that is crimped on to hose barbs. I have noticed when using the test functions, that whenever the rinse is turned off, the pump comes to an abrupt stop, but whenever I test the rocker panel function, it stops much smoother. Could the dema solenoids on the gantry for the side and top spray be the cause of the abrupt stopping? As far as I can recall, there is not an off delay on those solenoids to keep them open for a couple seconds after the pump turns off.

 

[MEP001]

Cavitation isn't from air leaks, it's from inadequate flow to the pump.

 

[Jeff_L]

How is your cat fed? Gravity or under pressure, and what size hose? I have two cat3535’s and both are gravity fed with 2” hoses. They run like champs.

 

[JGinther]

Water wizards plumbing design makes it where the wax doesn't work. When the main tank is filling, there is no pressure left for the wax hydrominder to draw wax. Most people end up 'choking' the inlet to the pump to make the pump have more suction, so that you can actually use what little wax there is in the mix tank. The problem is you have to be very careful when choking a pump with a ball valve, or you cause cavitation. A better plan is to scrap the factory design and do something else that actually works...

 

[toddmullens]

The pump is gravity fed with a 2” hose. I agree the design is poor in regards to the wax and high pressure soap draw. I am also aware of the choking of the supply to create enough suction. The pump is definitely not starved for water. I have some locations that the pump is smooth when it stops and others that stop very aggressively, and all are plumbed the exact same way. I am using a low pressure 1” hose for the bypass instead of a wire braid hose that was installed by the factory and you can see the hose bounce around whenever the pump stops on the pumps that have the tougher sounding stop. The pumps that stop smoothly have no movement in the bypas hose. What gets me is that it happens only on the rinse and not on the rocker panel option. You can tell there is much more turbulence in the bypass line whenever the rinse function turns off versus the rocker panel function.

 

[toddmullens]

Any suggestions you can recommend?

 

[toddmullens]

Cavitation isn't from air leaks, it's from inadequate flow to the pump.

Sorry, I assumed cavitation and sucking air caused the same result. Either way, I have adequate flow to the pump and the pump is not sucking air from any connection.

 

[toddmullens]

Water wizards plumbing design makes it where the wax doesn't work. When the main tank is filling, there is no pressure left for the wax hydrominder to draw wax. Most people end up 'choking' the inlet to the pump to make the pump have more suction, so that you can actually use what little wax there is in the mix tank. The problem is you have to be very careful when choking a pump with a ball valve, or you cause cavitation. A better plan is to scrap the factory design and do something else that actually works...

Any suggestions how to plumb it better

 

[Greg Pack]

Agree on the HP wax thing JGinther is talking about. I blend my wax in tank at a very concentrated solution(usually a red tip) so that I get adequate product without restricting the flow too much. Its a poor application technique on an IBA. I use two back to back CCP passes to ensure complete coverage on the car. A single pass will not cover the car due to the delay in product arriving at the nozzle. By the time the CCP starts coming out you're half way down the car.

Also, I'm assuming you're not letting the unloader leak? This will allow air into the water stream when running.

 

[Greg Pack]

Any suggestions how to plumb it better

On a first generation wizard I converted to a low pressure wax arch. I used the CCP output on the PLC to power a dual DPDT relay. I used this rellay to simultaneously cut the power to the HP coil and use the other side of the relay to energize an air solenoid feeding a flojet G57, which sent CCP out to a rain arch I installed. It works WAY better than HP wax.

 

[toddmullens]

Agree on the HP wax thing JGinther is talking about. I blend my wax in tank at a very concentrated solution(usually a red tip) so that I get adequate product without restricting the flow too much. Its a poor application technique on an IBA. I use two back to back CCP passes to ensure complete coverage on the car. A single pass will not cover the car due to the delay in product arriving at the nozzle. By the time the CCP starts coming out you're half way down the car.

Also, I'm assuming you're not letting the unloader leak? This will allow air into the water stream when running.

No leaks on anything including the unloader

 

[toddmullens]

On a first generation wizard I converted to a low pressure wax arch. I used the CCP output on the PLC to power a dual DPDT relay. I used this rellay to simultaneously cut the power to the HP coil and use the other side of the relay to energize an air solenoid feeding a flojet G57, which sent CCP out to a rain arch I installed. It works WAY better than HP wax.

That’s a great idea...doesn’t help with broke valve spring issue, but great idea all the same!

 

[JGinther]

Any suggestions how to plumb it better

1. Run all of the hydrominders off of a constant pressure supply (like a booster pump with bladder tank and check valve) so that the pressure is there to make the venturi effect work in the hydrominder eductor.
2. Tee in a high pressure solenoid off of the outlet of the pump with an injector. The outlet of the injector would plumb back to the inlet. This would cause a lower pressure application depending on the size of the solenoid and plumbing used.
3. Better yet, do what Greg Pack did.

So is your valve spring problem only at one place, or multiple places? How many failures?

 

[toddmullens]

I would say I am having Springs break on at least 11 out of 16 pumps, some more often than others. It’s usually the inlet valve spring on the left side of the head if you are facing the pump head, sometimes it’s both the inlet and outlet valve spring on the left side. It’s done it on both 1.0 and 2.0 water wizards. It randomly happens but is very noticeable when there is a busted spring.

 

[JGinther]

No Reclaim, no change in pulley sizes, no pressure over 1000 psi, no hp soap option, no choking of the inlet? Everytime I have ever seen valve spring failures, it been from pump overspeed (not sizing the pulleys right for the pump rating).

 

[Greg Pack]

I would say I am having Springs break on at least 11 out of 16 pumps, some more often than others. It’s usually the inlet valve spring on the left side of the head if you are facing the pump head, sometimes it’s both the inlet and outlet valve spring on the left side. It’s done it on both 1.0 and 2.0 water wizards. It randomly happens but is very noticeable when there is a busted spring.

So what is the symptom of a busted spring?

 

[toddmullens]

It makes a distinct sound and runs very rough. You can see the high pressure hose pulsate as well.

 

[toddmullens]

No Reclaim, no change in pulley sizes, no pressure over 1000 psi, no hp soap option, no choking of the inlet? Everytime I have ever seen valve spring failures, it been from pump overspeed (not sizing the pulleys right for the pump rating).

Same pulleys have been installed for 10 + years. I do have hp soap option but it’s sealed up tight using hose barns and hose clamps and not polytube.

 

[mac]

Always nice to see how mep tries to correct/impress us with his knowledge. While he is correct in what he states, he again misses the overall picture. Whether the issue is lack of water or air being sucked into the pump, the results are the same. In other words it sounds like the pump has rocks in it, and the harmful results are the same. Both will destroy a pump head and or its pieces.

 

[JGinther]

Same pulleys have been installed for 10 + years. I do have hp soap option but it’s sealed up tight using hose barns and hose clamps and not polytube.

Wait, so they are not factory pulleys? Or do you mean you still have the factory ones? I'm betting they are factory, as I wouldn't see any need to change... I think I would delete the HP soap option and save some money... I really doubt this is the case, but perhaps you have chemical working against the springs over time... Do you choke the pump with a ball valve? As far as stopping the pump, as long as the unloader is set at 1000 psi, the relief should open and the pump shouldn't feel any difference. Is there odd coloration of the valve springs as compared to new ones when you remove them? I have also seen this once where an electrician replaced a motor with a high speed motor accidentally... Wow! was that a mess! 2 or three valve springs broke, but the pump survived.