Eminent Technology tonearm ET--2

I am finding that my pumps may not provide enough air pressure for the tonearm.

Is it possible dust builds up in the tonearm manifold and one needs to blow dust out?  How do you do it?

Is it possible the inline filter is plugged.  I use a Motor Guard Corp. D-13.  How would I tell if plugged and can I clean?

Should I buy a new pump?  I have one called Takatsuki SPP-6GA and one WISA D.B.G.M. Audio Pump.  Is one preferred over the other?  What is the airflow in each?

How do I measure the airflow coming out of the pump?

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