Pressure relief valve on Polaris 280

[bware]

Does anyone know if this valve at the pool wall is supposed to release 1) some constantly 2) only if it is defective?
My cleaner is very slow and will not climb or run strong as when new. It is only 3 years old and I've replaced a defective backup valve already and will replace the two feed line swivels today. Wheel gear teeth still in good shape and all wheels turn when engaged. Floats, b/u valve positioned per mfr's instructions as well as hose length specs per pool size.
I'm hoping either the swivels (i know one is leaking especially during backup) or the pressure relief valve is the culprit..otherwise I'll punt to the all knowing pros in this forum for input.
Thanks in advance.

 

[Defgufman]

Does the float in the back have water in it?

 

[bware]

Does the float in the back have water in it?

No. Checked that first.

 

[bware]

No. Checked that first.

I have found the probable answer to my question on the relief valve from Pool Supply Sales.com....looks like I need a new one. See below:



THE PRESSURE RELIEF VALVE MAY BE DEFECTIVE…

Solution: Located on the quick disconnect wall fitting is the pressure relief valve. The Pressure Relief Valve is designed to discharge water pressure in an event of a blocked line. The spring loaded Pressure Relief Valve adds a layer of protection, safeguarding your Polaris 280 from any possible damage. Over time the Pressure Relief Valve will go defected. If the Pressure Relief Valve is discharging an abnormal amount of water pressure, which slows the cleaner down, then it needs to be replaced.

 

[bware]

Update:
After replacing the pressure relief valve, the Polaris is running up to speed as when new again.