Porsche 928 Workshop Manual page 236

928
Differential. Transaxle Svstem
Procedure
2. Check pilot pressure valve opera-
tion as described below:
Use System Tester 9288 to activate
transverse lock solenoid (Drive links /
Check transv. lock menu) with 1 - 2
pulses.
Then switch to pressure reduction
position and read off gauge pressure
after a short interval (to allow for
gauge damping).
For specifications, refer to
p. D39-215.
3. Follow check by bleeding the
transverse lock and correcting the
reservoir level.
Execution 1 Notes
- Connect System Tester 9288 along with adapter
line 9288/l to diagnosis socket (located next to the
passenger's seat under the booster cover).
Bleed pressure gauge by clocking lock solenoid
valve complete with System Tester in "Drive links /
Bleed position" menu and allow brake fluid to es-
cape from the pressure gauge at the bleeder valve
until it is free from air bubbles. (Use collector bottle).
For this purpose, leave bleeding device connected
to reservoir and leave bleeding line clamped. Bleed-
ing pressure approx. 1.5 - 2.0 bar.
Close bleeding valve and press stop buttom. Select
pressure reduction position.
Switch off bleeding device.
Important note
If pilot pressure is too high (before replacing a valve),
build up a lower pressure and reduce pressure by
switching off the ignition, thus deviating from the
previous testing procedure.
Pilot pressure may drop by max. 0.2 bar within
5 minutes.
- After disconnecting the pressure gauge, use the
System Tester (Drive links Select bleeding
menu) and allow brake fluid to escape at bleeder
valve of the transverse lock slave cylinder until fluid
is free from air bubbles.
- Correct reservoir level with accumulator fully
charged (after pump unit has switched off automat-
ically). Do not fill above "max. mark".
Screw on reservoir lid. Open venting line at reser-
voir again. Disconnect System Tester.
a
PSD-Diagnosis / Troubleshooting D39 - 217
Printed in Germany - XXVII, 1991