Genuine Volvo 780 Brake Booster

Volvo 780 Brake Booster Parts and Q&A

• Brake Booster
  3516093
  Q: How to check the power brake function and carry out the removal and installation of the brake booster on Volvo 780?

  A:

  To check the power brake function, deprive it of vacuum by depressing the brake pedal about five times, then depress the brake pedal and start the engine - its position should drop slightly if functioning properly. For a pressure test of the system, brake pedal pressure should be applied for approximately 20 seconds and then high pedal pressure applied for 5 seconds. pedal position should not drop as a drop in the pedal position indicates brake fluid leakage or a booster vacuum leak. For removal and installation purposes, first disconnect the negative battery cable and then remove the master cylinder and disconnect the vacuum hose and check valve from the booster. If necessary, disconnect the fuel filler and the vacuum pump and place them out of the way. Inside the vehicle, remove the soundproofing and disconnect the brake pedal rod, remove the power booster retaining nuts and remove the power booster. Before the installation of the new booster check the valve seal and replace it if necessary, making sure that the flange of the seal is correctly positioned. For the 2 x 8 inch booster, place the sealing washer and seal on the booster and then place the booster back in the car. Reconnect the brake pedal to the booster rod, refit the soundproofing and install the master cylinder, check valve and vacuum hose. Finally, bleed the brakes and clutch if fitted, and reconnect the negative battery cable.