Hyundai Coupes/Sedans 1986-1993 Repair Guide

Master Cylinder


Be careful not to spill brake fluid on the painted surfaces of your car. The brake fluid will cause damage to the paint.


See Figure 1

  1. Disconnect the fluid level sensor.
  3. Disconnect the brake tubes from the master cylinder and cap them immediately to prevent the entry of moisture into the system. On V6 Sonata with rear disc brakes, disconnect the brake tubes without removing the proportioning valves.
  5. Unbolt and remove the master cylinder and gasket from the booster. If the gaskets are worn, replace them. On V6 Sonata with rear disc brakes, there is a rubber 0-ring located on the master cylinder cartridge that seals the unit to the brake booster. If this seal is worn or damaged in any way, replace it.

Click image to see an enlarged view

Fig. Fig. 1: Typical master cylinder assembly

  1. Before installing the master cylinder, check the pushrod-to-master cylinder clearance as follows:
    1. On 1986-89 Excel, measure the master cylinder pushrod clearance using the accompanying illustration and the following formula: A = B - C - D. A should be 0.4-0.8mm.
    3. On Sonata with rear drum brakes, with a Vernier caliper measure the distance from the booster front shell surface to the booster pushrod end (dimension "A"). It should be 37.35-37.65mm.


Master cylinder pushrod clearance adjustment is not required on Sonata with rear disc brakes and the 1990-93 Excel, Elantra or Scoupe.

  1. If the pushrod-to-master cylinder clearance is not as specified, adjust by changing the pushrod length by turning the adjusting screw on the pushrod.
  3. Position the master cylinder to the booster and install the mounting bolts. Torque the mounting bolts to 10-16 ft. lbs. (14-22 Nm) for Scoupe or 9 ft. lbs. (12 Nm) for remaining models.
  5. Connect the brake tubes to the master cylinder. Torque the tubes to 9-12 ft. lbs. (13-17 Nm).
  7. Bleed the brake system. Connect the negative battery cable. Road test the vehicle.