Audi TT 2007 - Clutch Master Cylinder and Clutch Slave Cylinder, Function Test

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– Remove the protective cap on the vent screw -arrow- and
connect bleeder bottle hose -A-.
– Switch on brake filler/bleeder unit.
• Working pressure 2.0 bar positive pressure.
–
Now open the vent screw approximately
1
/
4
turn and let 100
cm
3
brake fluid drain out.
– With the vent screw open, press the clutch pedal by hand very
quickly 15 to 20 times from one stop to the other (approxi‐
mately 2 presses per second).
– Close the vent screw.
– Switch the -VAS 5234- off and completely release the pres‐
sure on the bleeder unit.
– Now press the clutch pedal slowly 10 times from stop to stop.
– Check clutch system function when doing so.
– Pull off bleeder hose and set protective cap in place.
– Remove the -VAS 5234- from the brake fluid reservoir.
– Install the air filter housing. Refer to ⇒ Fuel Injection and Ig‐
nition; Rep. Gr. 24 ; Removal and Installation .
1.3 Information Regarding the Removal and
Installation of the Clutch Master or Slave
Cylinder
♦ If the clutch master or slave cylinder is to be replaced as a
result of a suspected defect, it must first be checked for func‐
tion. Refer to
⇒ “1.4 Clutch Master Cylinder and Clutch Slave Cylinder,
Function Test”, page 13 .
♦ If the clutch slave cylinder is removed from the transmission
with hose/line assembly connector, do not operate (depress)
clutch pedal any more. Otherwise, the pistons are pushed out
of the clutch slave cylinder and thus damaged.
♦ Carefully actuate the clutch pedal after installing the clutch
slave cylinder. If an abnormally difficult pressure point is no‐
ticed when depressing the clutch pedal, do not depress the
clutch pedal any further. The plunger of the clutch slave cyl‐
inder was probably guided past the clutch release lever. Be‐
yond a pedal force of approximately 300 N, clutch slave
cylinder is destroyed.
1.4 Clutch Master Cylinder and Clutch
Slave Cylinder, Function Test
Before replacing master or slave cylinder, you must first carry out
the corresponding tests in the event of the following problems.
Noises when actuating the clutch:
♦ First check the over-center spring and the clutch pedal switch
for noises.
♦ If noises are heard, remove the over-center spring and repeat
the test.
♦ Replace affected component.
Audi TT 2007 ➤
Manual Transmission - Edition 10.2009
1. General Information 13