[Fot] A type O.D.

[Randall]

> Hello can anyone tell me the function of the non return valve 
> on the A type And if the strength of the spring is changed 
> what would be the result

It essentially functions as the exhaust valve for the hydraulic pump.  On
the pressure stroke, the ball lifts and allows oil into the accumulator;
then when the pump piston returns, the ball seats and keeps oil from flowing
back into the pump.

If the existing spring is too weak, then a stronger one will help build
pressure faster (or at all).  There's an old "Mr Finespanner" article on the
web somewhere, talking about the "fix" being to shim up that spring.
http://tinyurl.com/mt25ynm

But mine was apparently strong enough, as I couldn't tell any difference at
all with a shim (so I left it out).

Randall