Genuine Volvo S40 Brake Master Cylinder

Volvo S40 Brake Master Cylinder Parts and Q&A

• Master Cylinder
  36001340
  Q: What should you know about the Brake Master Cylinder before starting work on the hydraulic fluid and master cylinder on Volvo S40?

  A:

  Before engaging in work, know the dangers of hydraulic fluid. Overhaul of master cylinder is not possible and internal components are not available separately and if any fault occurs the unit has to be renewed. Begin by disconnecting the battery negative lead and then depression of the brake pedal should be repeated repeatedly to collapse any residual vacuum in the servo and siphon as much fluid as possible from the master cylinder reservoir using a syringe or old poultry baster, being careful not to siphon through the mouth as it is poisonous. Disconnect any wiring connectors from the reservoir/master cylinder, and manual transmission models, disconnect the clutch master cylinder fluid hose from the side of the reservoir, being prepared for fluid spillage and plugging the open ends. Next, disconnect the hydraulic pipe unions from the master cylinder, again being prepared for spillage of fluid and plugging off or capping the opening to prevent contamination to anyone. Remove the nuts holding the master cylinder to the servo, pull it off the servo studs being careful not to spill hydraulic fluid on the paintwork. If required, undo the screw and lift the reservoir from the master cylinder body checking the condition of the two seals and renewing if necessary. For refitting, lubricate the seals with clean brake fluid if they are removed, install the reservoir back to the master cylinder and tighten the retaining screw securely. Adjust the master cylinder into position in the servo unit and tighten the tightening nuts according to the indicated torque. Refit the brake pipes without doing up the union nuts entirely at this point but reattach the fluid hose to the reservoir lubricating the hose end with brake hydraulic fluid for easier fitting. Reconnect reservoir/master cylinder electrical connectors, absorbent rags under brake pipe unions on master cylinder, filled reservoir with clean hydraulic fluid specified type. Tighten the brake pipe unions securely if hydraulic fluid is found to leak out and then bleed the hydraulic system, including the clutch hydraulic system for manual transmission models. After bleeding, pressure test the master cylinder by depressing the brake pedal hard and holding it down for 30 seconds, and then release the pedal and check for leaks around the master cylinder pipe unions.