Clutch Master Cylinder: Service and Repair

Master cylinder, removing and installing

Special tools and misc. equipment required






- 3094 Hose clamps






- VAG 1331 Torque wrench

Removing

- First check whether a coded radio is fitted. If this is the case obtain the anti-theft coding.
- With the ignition switched off disconnect the battery Ground (GND) strap.
- Lay a sufficiently lint-free cloth in plenum chamber below return hose to brake fluid reservoir.






- Clamp shut the return hose -A- to brake fluid reservoir using hose clamp 3094, pull connecting line off master cylinder and seal.
- Remove grommet for return hose -A- from bulkhead.
- Pull out clip -C- to stop using screwdriver and then pull out line/hose assembly -B- slightly.
- Disconnect electrical connector for brake fluid level sender from brake fluid reservoir.






- Remove bolt -1-.
- Using inside Torx bit T45, carefully unscrew bolts -3- and -4- from brake servo.
- Remove cover below instrument panel. Refer to






- Detach clutch pedal from master cylinder by prying out securing clip for pin with screwdriver -arrow 1- and pulling out pin -arrow 2-.






Note:
Make sure that clutch pedal switch -1- is not pressed out of securing clip. This will damage the thread of the switch and it would have to be replaced.
To make sure sufficiently secure seating, a clutch pedal switch -1- may be installed only once.

- Unbolt (-arrows 2-) master cylinder -4- from within passenger compartment.
- Remove mounting bracket securing bolt (arrow 3).
- Pull complete foot pedal cluster slightly into passenger compartment.
- Remove master cylinder.

Installing

Installation is carried out in the reverse sequence, when doing this note the following:






- Install master cylinder so that seal -1- and washer lie behind mounting bracket.
- Tighten bolts -2- to 20 Nm
- Press connecting line -3- with guide (arrow A-) into notch (-arrow B-) in mounting bracket.

A second mechanic is required for the next work step.






- Push complete foot pedal cluster forward to bulkhead and insert bolt (-arrow-).
During this step, from plenum chamber, the second mechanic must guide line/hose assembly into master cylinder.






- Tighten brake servo securing bolts -3- and -4- to 25 Nm
- Then tighten securing bolt -1- for brake fluid reservoir -2-.
- Attach connector to brake fluid level sender on brake fluid reservoir.






- Press in clip -C- to stop.
- Push line/hose assembly -B- into master cylinder until it audibly engages.
- Test line/hose assembly by tugging on it.
- Insert rubber grommet -D- for return hose -A- into bulkhead.
- Push return hose -A- to stop on connecting line of master cylinder.
- Remove hose clamp 3094.





- Tighten securing bolt (-arrow-) for foot pedal cluster to instrument panel carrier to 25 Nm
- Connect master cylinder to clutch pedal. Engage new pin in clutch pedal.
- Bleed clutch system after installing master cylinder.


Checking and adjusting clutch pedal switch

- Clutch pedal is not operated.






- Check adjustment of switch -1- over clutch pedal as follows:

Switch -1- must contact clutch pedal -4-.
Required play -a- at switch -1- must be a maximum of 0.5 mm.
Securing clip -2- should contact mounting bracket -3-. A maximum of 0.5 mm gap -b- is permitted.






- To adjust switch, you must hold securing clip and turn switch.

Notes: During adjustment, the clutch pedal must not be operated.
To make sure sufficiently secure seating, a switch may be lifted only one time.

Installing new clutch switch

- Clutch pedal is not operated.
- Press switch -1- into mounted securing clip -2- to stop against clutch pedal.
- Check and adjust clutch pedal switch.
- Attach connector