Thank you for the reply. I didn’t realise it was there.

When I done the pressure test it soon got up to pressure 81 Psi but when I attempted a flow test I noticed the amount of air.

The cars owner said he put 3 gallons in. We may have lost a little but he has now put another 2 gallons in. I am awaiting a new union with the filter attached that I just realised was fitted before I try again.
The owner changed the pump himself and drained the tank. The filter he just fitted last week and he said there was not much fuel came out.
I will report back
Thanks