[Chris R]

?

[Dynafoam]

Chris,

In open-flow conditions a pump may be able to maintain its' specified flow-rate, but may still fail to achieve its' normal opperating pressure, due to an internal leak (eg past pistons)  when its' output becomes restricted.

[Cloverleaf]

I have just had the same problem with the same pump

The 135 psi pump on my Ninja gave up after 3.5 years.
I fitted a 160 psi Totton pump from Ashbys. After a few months it became difficult to prime and had lost pressure and flow, so it seemed.
I checked machine thoroughly, pipes conectors etc.
Sent pump back to Ashbys and they found that the pump head was fualty and they imediatly sent me a new pump  and I must add it was carriage free

If your machine has a flow control valve, try putting your finger over the outlet in the tank when the valve is open. If you can stop the water flow then you will find the pump is probably fualty.

Hope this helps , John