Porsche 928 Workshop Manual page 277

39
Differential. transaxle system
928
2. Bleed the pressure reservoir and lock so-
lenoid valve as follows:
Open the bleeder valve on the lock solenoid
valve. Push the electrical plug onto the
pump wtih the ignition switched on. Pull off
the electrical plug and close the bleeder
valve as soon as the brake fluid emerges
wtthout air bubbles (use a collection bottle).
Now fully charge the pressure raservoir.
Push on the electrical plug. As soon as the
pump is heard to switch
off, pull off the
electrical plug
and reduce the pressure at
the bleeder valve of the lock solenoti valve
to zem (slowly open the bleeder valve I use
a collection bottle).
Important: The system is under a press-
ure of up to 180 bar. Wear goggles and
protective gloves.
Note
;tr a filling and bleeding untt is not connected,
always check the level in the fluid reservoir
between bleeding processes and top up with
brake fluid if necessary.
3. Repeat the last process (fully charging
the pressure reservoir and then reducing
the reservoir pressure to zero) approx.
f-2 times (brake fluid must be free from
air bubbles).
4. Bleed lock cylinder and pressure lines.
For this purpose, the lock solenoid valve is
pulsed with system tester 9289. The high
pressure present at the solenoid valve there-
by enters the pressure lines in pulses and
reaches the lock cylinder via the non-return
valve.
Drain off brake fluid at the bleeder valve of
the lock cylinder until no more air bubbles
appear.
5. After completing the assembly and bleeding
work, correct the brake fluid level
-with the pressure reservoir fully charged.
l
039 - 260
a
PSD diagnosis/Troubleshooting
Printed in Gemmy - xxxv. 1996