Audi Workshop Service and Repair Manuals

Removing and installing clutch master cylinder Special tools and workshop equipment required

t  Hose clamps, up to Ø 25 mm -3094-

t  Pliers -V.A.G 1922- Removing   Note t  If you suspect a defective clutch master cylinder, perform function test prior to renewing → Chapter „Notes on removing and installing clutch master cylinder and slave cylinder“. t  When performing work in the footwell, put cloths on the carpet to protect it from possible brake fluid spills.

–  Pull off rubber seal on plenum chamber in -direction of arrow-. –  Detach cover -1- from plenum chamber.   Caution t  Follow steps required when disconnecting battery → Electrical system; Rep. Gr.27. t  Make the customer aware that the driver must NOT rest his/her foot on the clutch pedal for long periods of time. This could impair the self-bleeding function of the clutch system as the vent opening in the master cylinder can no longer function. –  With the ignition switched off, disconnect battery earth strap → Electrical system; Rep. Gr.27.

–  Use screwdriver to pry off the two caps -3-. –  Unscrew nuts -4- and detach the two wiper arms -2-. –  Pull off clips -1- and detach cowl panel grille -5-.

Take the electronics box out of the plenum chamber as follows: –  Unscrew bolts -arrows- and take off the cover.

–  Use screwdriver to carefully pry off retaining strap -arrow-. –  Lay aside engine control unit with connectors attached.

–  Unplug connectors -2- at connector console. –  Unscrew electrical wiring connection -1-.

–  Release catches -arrows- and lift auxiliary relay carrier out of electronics box. –  Pull engine wiring harness together with rubber grommet out through opening in electronics box.

–  Remove nuts -arrows- and lift out electronics box -1-.   Note t  In the following steps make sure that no brake fluid escapes into the plenum chamber or onto the gearbox below. If this does happen, clean the affected area thoroughly. t  When performing work in the footwell, put cloths on the carpet to protect it from possible brake fluid spills.

–  Clamp off supply hose -A- from brake fluid reservoir using hose clamp -3094-. Disconnect hose from clutch master cylinder and plug hose. –  Remove rubber grommet from bulkhead above connection pipe for supply hose. –  Lever out retaining clip -C- using a screwdriver and pull out pipe/hose assembly -B- slightly.

–  Unscrew bolt for brake fluid reservoir -1- and unplug connector for brake fluid level warning contact downwards.   Note The brake fluid reservoir does not have to be removed.

–  Remove vacuum pipe leading to brake servo -1-. –  Remove the two TORX bolts -arrows-.   Note t  To simplify the illustration, the brake fluid reservoir has not been included. t  The brake fluid reservoir must be moved slightly to the side in order to unscrew the upper TORX bolt. –  Remove storage compartment on driver's side → General body repairs, interior; Rep. Gr.68. –  Remove over-centre spring → Chapter.

–  Disconnect brake pedal from brake servo → Brake system; Rep. Gr.47.

–  Disconnect steering column from steering box -arrow A- → Running gear, front-wheel drive and four-wheel drive; Rep. Gr.48. –  Unplug connectors from clutch pedal switch -F 36--1-, brake light switch-2- and accelerator pedal module -3-. –  If fitted, unplug connector from clutch pedal switch for engine start -F194-. –  Unscrew securing bolt for mounting bracket -arrow B- and remove entire pedal cluster.

Release master cylinder operating rod from clutch pedal as follows:   Note t  When releasing the operating rod, make sure that clutch pedal does not collide with mounting bracket for clutch pedal switch -arrow-. The mounting bracket could otherwise break off. t  The clutch pedal switch -F 36- → Item and clutch pedal switch -F 194 - → Item can only be installed once so as to ensure a firm fit in pedal cluster. –  Apply spark plug connector pliers -V.A.G 1922- in clutch pedal recesses, press on sides of retaining clip → Item and detach clutch pedal from clutch master cylinder.

–  Detach retaining clip -1- and remove clutch pedal -2-. –  Unscrew bolts -3- and remove clutch master cylinder -4-.

Installing Installation is carried out in reverse sequence; note the following: –  Fit clutch master cylinder -4- and tighten bolts -3- to 20 Nm.

–  Insert retaining clip -1- in clutch pedal. –  Lock clutch pedal in position by pressing in -direction of arrow-. Make sure retaining clip -1- engages correctly in clutch pedal.

A second mechanic is required for the next step. –  Insert entire pedal cluster and tighten bolt -1- by hand. The second mechanic should guide pipe/hose assembly into clutch master cylinder from plenum chamber.

–  Tighten bolts for brake servo -arrows- to 25 Nm.

–  Press in retaining clip -C- as far as it will go. –  Insert pipe/hose assembly -B- in clutch master cylinder and make sure that it engages audibly. –  Fit rubber grommet -D- onto connecting pipe for supply hose -A- at bulkhead. –  Push supply hose -A- from brake fluid reservoir on as far as it will go. –  Remove hose clamp -3094-.

–  Screw in securing bolt -1- for brake fluid reservoir and plug in connector at brake fluid level warning contact.

–  Tighten hexagon socket head bolt -arrow B- for securing pedal cluster to dash panel carrier to 25 Nm. –  Plug in connectors -1-, -2- and -3-. –  If fitted, attach connector for clutch pedal switch for engine start -F194-. –  Connect brake pedal to brake servo → Brake system; Rep. Gr.47. –  Secure steering column to steering box -arrow A- → Running gear, front-wheel drive and four-wheel drive; Rep. Gr.48. –  Install over-centre spring → . –  Install storage compartment on driver's side → General body repairs, interior; Rep. Gr.68. –  Bleed clutch system → Chapter.

–  Insert electronics box and tighten nuts -arrows- to 4 Nm. –  Route engine wiring harness and plug in connector in connector console. –  Install engine control unit → Rep. Gr.23 or → Rep. Gr.24. –  If applicable, install auxiliary relay carrier and auxiliary fuse carrier → Electrical system; Rep. Gr.97. –  Press on cover (hand-tight) and tighten bolts in diagonal sequence to 4 Nm. –  Follow steps required after connecting battery → Electrical system; Rep. Gr.27.