This weekend, I made my own pressure tester on the weekend which can test for either air or water.
I tested the return lines with water. They held pressure with a drop from 30 to 29.5psi over 5 minutes.
When I tested the suction lines with water at the pump, I found an immediate leak where the suction line comes out of the concrete. I was able to temporarily fix this with a piece of rubber and hose clamp.
When testing again, I still have a drop from 30 to 20 psi in two minutes. I have checked my tester and above ground pipe including temporary fix with soapy water, but found no leak. I tested the suction line again with air to listen for air leak, but I could not hear anything.
The suction line from the pump has a 3 ft drop from the pump in the first 12ft of run, and an additional 25 ft under the concrete pool deck. I tried to estimate how far down the line the leak is by letting the pressure drop to zero and measuring how much water it takes to refill the pump reservoir. It took just over 9 litres of water to refill. Given the cross section of 1.5 hose, I estimate the leak about 26’ down from the pump (I recognize this is a very rough estimate, but should be good enough to say the leak it is very much under my concrete deck). From photos I took photos during construction of the pool, my suction plumbing has a single line down most of its length from the pump with a ‘T’ just before the skimmer to split between the skimmer and an in wall vacuum port.
My pump is functioning fine, and since I temporarily fixed the first leak, I no longer see any bubbles in my pump reservoir, and the water doesn’t ‘gurgle’ out of the line when I turn the pump off.
I have a couple questions
1) Is 30psi appropriate for this test?, or Should I measure at a lower pressure?
2) Is the pressure drop in the suction line significant enough to cut the concrete and fix?
3) Would a stethoscope on the concrete allow me to listen for the air leak?
4)I have had problems with my liner lifting in the deep end.
Is there any chance that this leak is related to my lifting liner?