The 400 psi pump is mounted on top of the motor. When the pump leaks it goes into the motor.. so then you have short motor life and the capacitor can soon give up as well.
Why does the pump start leaking after not much use? Because in the Ninja 400 psi the motor is under rated...the alloy bearing housing starts to wear because it cannot cope with the counter force of the pump and, therefore the spindle runs out of center causing premature wear of the bearings which acts on the piston. The piston then wears due to the spindle running out of true.
I called Pumptech in the US a few years ago...they said the motor fitted inthe Ninja is not suited to their 400 psi pump head.
Why did I call them? Because I was using a new motor from Ashbys every 3 months at £200 a time
Now take the Airflex...it has a BIG 1 horse power motor to the same pump head. If the pump leaks, it won't leak into the motor as is is mounted sideways.
In my experience, the seals will only need replacing every 6 to 8 months.
I'v had my Airflex nearly 2 years and not needed to change the pump motor.
The pump motor on the Airflex is unlikely to wear due to the counter force of the pump because of it's size.
In other words....I'd never buy a 400psi Ninja again
