Volkswagen Cars 2000-05

Master Cylinder

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Fluid Level Check





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Fig. Master cylinder level marks



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Fig. Wipe around the cap of the master cylinder to remove any dirt



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Fig. Remove the cap



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Fig. Add brake fluid that meets the DOT 4 specifications



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Fig. The fluid reservoir is translucent and the level easily checked

The brake fluid reservoir is located on the left side of the engine compartment at the firewall. Fluid level can be checked visually without removing the cap on this translucent unit. Brake fluid level will decrease slowly as the brake pads wear thinner. If the level is close to the MIN line, check the brake pads and/or shoes for wear before adding brake fluid.


NOTE
Some models do have a brake fluid level warning light. As the fluid level reaches the MIN (minimum level) the light may flash when driven over bumps or around corners. Check the brake lining thickness and top off as necessary.

If the reservoir constantly needs refilling, chances are there is a leak in the system. The entire brake system should be thoroughly inspected for any signs of leakage.

Fluid Recommendations & Fill



On all models covered by this manual, brake fluid that meets or exceeds DOT 4 specifications should be used in the brake system. DO NOT use DOT 5 fluid; the hydraulic system can be damaged.

On all models covered by this manual, brake fluid that meets or exceeds DOT 4 specifications should be used in the brake system. Do NOT use DOT 5 fluid; the hydraulic system can be damaged.



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Fig. Master cylinder level marks



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Fig. Wipe around the cap of the master cylinder to remove any dirt



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Fig. Remove the cap



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Fig. Add brake fluid of at least DOT 3 specifications

The brake fluid reservoir is located on the left side of the engine compartment at the firewall. Fluid level can be checked visually without removing the cap on this translucent unit. Brake fluid level will decrease slowly as the brake pads wear thinner. If the level is close to the MIN line, check the brake pads and shoes for wear before adding brake fluid.

If the reservoir constantly needs refilling, chances are there is a leak in the system. The entire brake system should be thoroughly inspected for any signs of leakage.

Removal & Installation





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Fig. Siphon out the brake fluid



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Fig. Remove the brake lines



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Fig. Remove the two master cylinder mounting bolts



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Fig. Cross-sectional view of a tandem master cylinder



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Fig. The fluid reservoir is installed directly onto the brake master cylinder



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Fig. Use a line wrench when loosening or tightening a brake line flare nut for the master cylinder


WARNING
If the vehicle is equipped with the Electronic Stability Program (ESP), the ESP pump must be actuated during the bleeding procedure, using the VAG 1551, VAG 1552, or equivalent scan tool, capable of activating the ESP pump.

  1. Cover the engine compartment to catch any residual brake fluid.
  2.  
  3. Remove the brake fluid from the reservoir using a siphon or clean baster-type tool. If equipped, disconnect the clutch hose from the reservoir. The clutch hose may have a crimped clamp securing it to the reservoir. Insert a small flat blade prytool through the opening on the side of the clamp and move the screwdriver side-to-side to open the clamp, then slide the clamp toward the reservoir and ease the off the hose. Clean all the brake line connections.
  4.  
  5. On A4 and 1998-00 Passat models, if the brake master cylinder reservoir spigots enter the side of the master cylinder bore, the reservoir is attached to the bottom of the master cylinder. The reservoir is released by pressing down on the locking catch and pulling the reservoir out of the master cylinder sealing plugs.
  6.  
  7. If equipped, remove the reservoir-to-master cylinder mounting fastener from the right side (engine side) of the master cylinder, then carefully remove the reservoir from the master cylinder. A trim panel removal tool works well to help remove the reservoir spigots from the master cylinder O-rings.
  8.  
  9. Using a line or flare wrench, remove the line connections from the master cylinder. Plug the lines to avoid contamination from debris.
  10.  
  11. Remove the mounting nuts and remove the master cylinder from the booster, taking care to no lose the O-ring.
  12.  

To install:

  1. Check the condition of the O-ring at the mounting flange of the master cylinder. Clean the mounting surfaces.
  2.  
  3. Install the master cylinder and torque the nuts to:
  4.  

Brake master cylinder-to-vacuum booster:



1990-00 Passat models: 15 ft. lbs. (20 Nm)
 
A4 and 1998-00 Passat models (replace): 37 ft. lbs. (50 Nm) 36 ft. lbs. (49 Nm)
 

  1. Install the brake lines and torque the connections to 11 ft. lbs. (15 Nm).
  2.  
  3. Thoroughly clean the reservoir with brake cleaner or isopropyl alcohol, then lubricate the spigots and O-rings with a light coating of clean brake fluid and install the reservoir. If equipped, install the clutch hose and secure with a new clamp. Fill the reservoir with fresh and an approved brake fluid and bleed the system as outlined in this section.
  4.  

With Anti-Lock Brakes
  1. Bleeding of the antilock brake system requires the use of a scan tool when ever the brake master cylinder reservoir runs dry. Therefore the removal of a defective master cylinder, on vehicles with ABS, should be performed by a professional repair facility.
  2.  

Without Anti-Lock Brakes
  1. To prevent brake fluid from spilling out and damaging the paint, place a protective cover over the fender.
  2.  
  3. Detach the negative battery cable.
  4.  
  5. Remove the master cylinder cap and remove as much fluid as possible.
  6.  
  7. Disconnect and cap the brake lines to keep dirt out.
  8.  
  9. Disconnect the wiring from any switches that may be screwed into the master cylinder.
  10.  
  11. Remove the two master cylinder mounting nuts and pull the master cylinder away from the booster.
  12.  
  13. The reservoir is held into the master cylinder by a press fit into rubber sealing plugs and can easily be pulled off. To reinstall, moisten the plugs with brake fluid and press it on.
  14.  


WARNING
Do not depress the brake pedal while the master cylinder is removed.

To install:

  1. Position the master cylinder and reservoir assembly onto the studs and install the washers and nuts. Tighten the nuts to 15 ft. lbs. (20 Nm).
  2.  
  3. Remove the plugs and connect the brake lines.
  4.  
  5. Bleed the brake system.
  6.  
  7. Install all remaining components in the reverse order of removal.
  8.  

 
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