Rinse normal, soap and wax selection causes loss of pressure

[cantbreak80]

Somewhere, there’s a ball valve…
From the water tank to each pump’s inlet.

This valve restricts the water supply to the pump so it will suck water AND soap or wax.

Fully open this valve and turn the pump on to the soap or wax selection.

Does the pump run smoothly now? If so, slowly close the ball valve until the pump just starts to “rattle”. Then, crack the valve open until the rattle just goes away.

Does Soap/Wax show now?



Cat instructions state:
• Line size must be a minimum of one size larger than the pump inlet fitting.

That doesn’t work in our applications. The inlet must be restricted in order to draw your chemicals. Many manufacturers plumb their gravity feed systems with 3/4" hose…therefore, the “throttling” valve is needed. 3/4" hose supplies all the water the pump wants…it will never draw from the chemical tank(s).

If the pump is plumbed with 1/2" hose from the gravity feed tank, no throttling is necessary.

You're welcome.

 

[Greg Pack]

CB80 he's not having a wax or soap supply issue. In his original post he describes what sounds like a water starvation issue or possible air intrusion into the suction side but I gather he's checked or replaced everything externally he can think of. I have suggested a flow test to the hose feeding the pump. If good inlet flow and no air intrusion found I think it's time to look at pump internals.

Strange stuff happens. Hell, just the other day I found a black piece of plastic almost the size of a dime stuck in a 1" hard water supply line feeding an IBA. I'm like "where did that come from?"

 

[CWdummy]

This has gone on long enough. What have you checked so far?

Found a cracked brass fitting on wax line that WAS NOT LEAKING, but letting air in. Go figure.

 

[CWdummy]

Somewhere, there’s a ball valve…
From the water tank to each pump’s inlet.

This valve restricts the water supply to the pump so it will suck water AND soap or wax.

Fully open this valve and turn the pump on to the soap or wax selection.

Does the pump run smoothly now? If so, slowly close the ball valve until the pump just starts to “rattle”. Then, crack the valve open until the rattle just goes away.

Does Soap/Wax show now?



Cat instructions state:
• Line size must be a minimum of one size larger than the pump inlet fitting.

That doesn’t work in our applications. The inlet must be restricted in order to draw your chemicals. Many manufacturers plumb their gravity feed systems with 3/4" hose…therefore, the “throttling” valve is needed. 3/4" hose supplies all the water the pump wants…it will never draw from the chemical tank(s).

If the pump is plumbed with 1/2" hose from the gravity feed tank, no throttling is necessary.

You're welcome.

 

[CWdummy]

Wax and soap lines from solenoids to tee below check valve at pump is 1/4”.

 

[Randy]

Found a cracked brass fitting on wax line that WAS NOT LEAKING, but letting air in. Go figure.

That'll do it. Is everything working like it should now?

 

[CWdummy]

That'll do it. Is everything working like it should now?

On that bay, yes. I have same problem in another bay. Will try to track that down in 2 weeks when I get back in town. Thanks for your help!!

 

[CWdummy]

Thanks for all the help!!

 

[Greg_T]

Found a cracked brass fitting on wax line that WAS NOT LEAKING, but letting air in. Go figure.

We find this in automotive air conditioning systems. Will leak under vacuum but not pressure, or vice versa. Makes diagnosis tricky. Well done on finding this one, and nice job from all those that provided knowledge and guidance.

 

[stampedecarwash]

it seems like your problem is fixed now, but I had a similar issue 2 month ago which was due to having the wrong nipple going too much into the check calve under tge hotwater tank, which prevented the calve from opening 100% therefore making the pump to starve on hot function such as wax and soap.