Repair Manual

MECHANICAL ELEMENTS CONTROLS
37
PRIMARY CIRCUIT – PRESSURE LOOSING
Lack of pressure in the primary circuit leads to the following situation:
The primary piston advances up to the pin, so it controls mechanically the secondary
piston.. The secondary piston reaches a fluid pressure that shall operate on the piston –
linings assembly moving it to the right, opening also the second exit of the rear circuit
(the by-pass circuit) increasing the pressure in this circuit.
In this moment, by means of the transducer, the warning light on the instrument panel is
on.
SECONDARY CIRCUIT – PRESSURE LOOSING
Both cylinder pistons go on. The caliper cylinders of the front brake shall normally
operate.
The secondary piston reaches its respective pin, but the pressure will decrease (due to
the failure).
BRAKE PUMP DISMOUNTING
Drain the brake fluid reservoir.
Disconnect the pump from the ICP transducer.
Dismount the four pipes from central
pump.
Unscrew the attachment nuts of the pump
on the servobrake.
Dismount the pump.
BRAKE PUMP REMONUTING
Before remounting, check the stroke of the servobrake push rod to be min. 30 mm.
Mount the brake pump on the servobrake, performing the dismounting operations in
reverse order.
After assembling with the brake fluid reservoir and fluid filling, no leakage must occur
in the surface of separation between the two elements.
VERY IMPORTANT : The I.C.P. transducer is mounted after the braking system
purging. The tightening moment = 2daNm. ICP sub-assembly is not reparable (ICP –
pressure decreasing indicator)
BRAKE PUMP
37 - 2
vnx.su