Mercury 40 Service Manual page 424

Under Water Strike (Valves Open)
Should the drive unit strike a submerged object while in forward motion, the shock rod (a)
will extend from the tilt cylinder (l). Fluid will attempt to exit the cylinder through the intercon-
necting passage. The rapid fluid flow will increase the pressure below the surge valve (k),
causing the valve to move, closing the oil return passage back into the accumulator (c). Oil
inside the up cavity is locked in a static position by the closed surge valve. As the shock rod
extends outward, the pressure inside the up cavity will reach sufficient pressure to open the
shock valve (p) which opens at 880-1110 psi. Oil will flow into the cavity created as the shock
rod & shock piston (a & n) moves away from the memory piston (m).
a -
b -
c -
d -
e -
g -
h -
k -
m -
n -
o -
p -
90-828631R3 MARCH 1999
Shock Rod
End Cap
Accumulator
Accumulator Piston
Accumulator Check Valve
f - Camshaft Lever
Manifold
Down Circuit Fast Transfer Valve
i - Down Circuit Slow Transfer Valve
j - Up Circuit Fast Transfer Valve
Surge Valve
l - Cylinder
Memory Piston
Shock Piston
Shock Return Valve
Impact Relief Valve
MANUAL TILT ASSIST
Page 5D-11