Seat Leon >> Subsequent bleeding of hydraulic system

Carry out subsequent bleeding when:

  • brake pedal travel is too long or so-called "soft brake pedal"

Subsequent bleeding requires the assistance of a second mechanic.

  • Depress brake pedal firmly and hold.
  • Open bleeder valve on brake calliper.
  • Fully depress brake pedal.
  • Close bleeder valve with pedal held down.
  • Release brake pedal slowly.
  • Connect brake filling and bleeding equipment - VAS 5234- .
  • Open bleeder valves in the specified sequence and bleed brake callipers.

Adhere strictly to work sequence when bleeding brake system.

Bleeding sequence:

  1.  Front left brake caliper
  2.  Front right brake caliper
  3.  Rear left brake caliper
  4.  Rear right hand side brake calliper

Use suitable bleeder hose. It must sit tightly on bleeder valve so that no air can enter brake system.

This bleed sequence must be carried out 5 times per brake calliper.

After bleeding the air from the system, test drive the vehicle.

When doing this an ABS regulation must be performed at least once!

Caution

Before performing the first test drive, make sure that the brakes are operating correctly.

Testing for leaks

Special tools and workshop equipment required

  • Brake tester - VAG 1310A-

  • Adapter M10 - V.A.G 1310/6-

 

  • Brake system (hydraulic unit, brake hoses, brake pipes and brake callipers) operating properly and free of leaks.

Check:

  • Remove bleeder valve at one of front brake callipers.
  • Connect the brake tester - VAG 1310A- and purge of air.
  • Apply pressure to brake pedal until the gauge indicates a pressure of 50 bar. The pressure must not drop by more than 4 bar within the test period of 45 seconds. If the drop in pressure is greater, then the brake master cylinder must be replaced.
    Bleeding hydraulic system following standard procedure
    Note Bleeding of the brake system is described using brake filling and bleeding equipment - VAS 5234- with adapter - VAS 5234/1- . A pressure of at least 2 bar is required to bleed the ABS h ...

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