The master brake cylinder (MBC) plays a key role in the operation of a vehicle's brake system. It transmits force from the brake pedal to the wheel cylinders, creating pressure in the system. When signs of malfunction appear (fluid leaks, a sinking pedal, reduced braking efficiency), disassembly and repair may be required. In this article, we will take a detailed look at how to disassemble the master brake cylinder, using popular vehicles as examples: VAZ 2107, Lanos, Opel Omega A, VAZ 2109, GAZ 3307.

When to disassemble the master brake cylinder

Before starting disassembly, it is important to make sure that the problem is indeed in the MBC. Below are signs that indicate disassembly is necessary:
  • Appearance of brake fluid leaks near the MBC;
  • The brake pedal slowly sinks when held;
  • Brakes work weakly, especially with repeated presses;
  • Brake fluid disappears without visible external leaks.
If such symptoms are noticed, you can proceed to checking and disassembling the cylinder.

Tools for disassembly

Before disassembling the master brake cylinder, prepare:
  • Wrenches of sizes 10, 12, 17 (depending on the model);
  • Flathead and Phillips screwdrivers;
  • A container for draining brake fluid;
  • Clean rags;
  • Brake cleaner;
  • Lubricant for assembly (e.g., brake fluid or a special compound);
  • A new repair kit (preferably original).

How to disassemble the master brake cylinder of a VAZ 2107

  1. Disconnect the negative battery terminal.
  2. Remove the brake fluid reservoir - carefully disconnect the hoses, having previously drained the fluid.
  3. Unscrew the brake lines coming from the cylinder.
  4. Unscrew the mounting nuts holding the cylinder on the vacuum booster.
  5. Remove the MBC and place it on a clean surface.
  6. Using a screwdriver, remove the retaining ring at the piston outlet.
  7. Extract the pistons, springs, and seals. Do this carefully to avoid damaging the parts.
Note: the pistons may be tight; you can use a wooden hammer handle, gently pressing from the opposite side.

How to disassemble the master brake cylinder of a Lanos

The algorithm is similar, but taking into account the layout of the engine compartment:
  • On the Lanos, it is recommended to remove the battery before disassembly to gain access to the MBC.
  • After removing the cylinder, the pistons are extracted carefully, especially if there is wear - they may stick.
  • Check the condition of the cylinder's internal surface - it should not have pitting or scratches.

How to disassemble the master brake cylinder of an Opel Omega A

Features:
  • On the Omega A, the MBC is installed together with the vacuum booster on a common panel. Access is limited, so a bit more time will be required.
  • Non-standard seals are used - it is better to purchase a repair kit in advance for the specific VIN.
  • Before removing the reservoir, it is recommended to pump out the brake fluid with a syringe or bulb.

Glavnyj-tormoznoj-tsylyndr.jpg

How to disassemble the master brake cylinder of a GAZ 3307

Considering that the GAZ 3307 is a truck, its cylinder is more massive and requires more effort to remove.
  • It is recommended to use a jack or stand for convenient access.
  • When removing the cylinder, take into account the weight and length of the lines.
  • The internal components are similar to those of passenger cars: pistons, springs, seals.
  • After extracting all components, wash the housing with cleaner, dry it, and proceed to inspection.

How to disassemble the brake cylinder of a VAZ 2109

On the VAZ 2109, two types of MBC may be used - with separate or common circuits.
  • Disassembly begins with removing the reservoir and brake lines.
  • Next, unscrew the fasteners to the vacuum booster.
  • After removing the MBC, disassembly is standard: retaining ring, pistons, seals.
  • Pay attention to the wear of the rubber seals - if they have lost elasticity, the cylinder will not work even after cleaning.

What to do after disassembly

  1. Thoroughly wash all parts with cleaner.
  2. Inspect the internal surface of the cylinder: the presence of scratches, traces of corrosion, or scoring is a reason for complete replacement.
  3. Install a new repair kit, lubricating the rubber parts with brake fluid.
  4. Assemble the cylinder in reverse order.
  5. After installation, be sure to bleed the brake system.
Knowing how to disassemble the master brake cylinder, you can save on repairs and independently fix some of the problems related to the brake system. This is especially relevant for vehicles with a simple design: VAZ 2107, VAZ 2109, GAZ 3307, Lanos, Opel Omega A. The main thing is to be careful, avoid contamination of components, use quality parts, and not forget about safety.