Genuine Mazda RX-7 Brake Master Cylinder

Mazda RX-7 Brake Master Cylinder Parts and Q&A

• Master Cylinder
  F065-43-400R-0B
  Q: How can the Brake Master Cylinder be serviced, and what steps should be taken to ensure proper installation and operation on Mazda RX-7?

  A:

  Get all the fluid out of the differential and then clean the parts, as cleaning will not be easy when the differential is still assembled; the gears in particular will be required to be clean and dry. Check anything that has been damaged in visible ways, as broken or chipped teeth in the gears, and the bearings for roughness of travel, wear or damage. Look at the front oil seal at the point where it connects with the propeller shaft and presence of oil will prove the failure of the pinion oil seal. Red lead or engineer blue that can be found in most auto supply stores can be used to check the tooth contact between the ring gear and pinion gear. Brush a little red or blue engineer paint on the two sides of some half a dozen or eight teeth of the ring gear, and then turn the ring gear itself a few times forward and back. Look at the teeth pattern, with heel contact showing that the drive pinion is too far and thus a spacer is needed to bring it nearer and toe contact indicating that the drive pinion is too near and thus pinion spacers are required to move the pinion. The difficulty in achieving the right spare parts, the complexity of the procedures, and the necessity of the use of the special tools makes it reasonable to send the home mechanic to a Mazda dealership or a professional auto repair shop doing the same job to have the differential assembly and the information gathered during the procedures.
• Master Cylinder
  FB02-43-400R-0D
  Q: What steps should be followed for a Brake Master Cylinder overhaul on Mazda RX-7?

  A:

  Before disassembly, it should be provided with a master cylinder, overhaul kit that will include all the parts needed to get a replacement. Start with depleting too much fluid in the master cylinder and reservoir. Take out the fluid level sensor which is on the right side of the reservoir by pinching the tab and pulling it out together with the top and the float. Uncouple the reservoir with the master cylinder by disconnecting its two bushings. Then remove the joint bolt, the check valve and the spring at the bottom of the master cylinder; taking note of the position of the check valve. The rest of the parts will then be removed off of the cylinder bore, the stop ring being the first part, followed by the stop washer, using a screwdriver. Reversal of the cylinder to take off the primary piston assembly and spring. With the secondary piston assembly, use a screwdriver to push it into the secondary piston assembly, unscrew the stop bolt at the top and connect the guide pin into the stop bolt opening, and release the pressure to relieve the assembly without damaging the piston cup, compressing air can be used. Take out the secondary piston spring and clean all the parts in clean alcohol or brake fluid, without using gasoline or kerosene and blow them off with compressed air where possible. Check the bore of the cylinder and the pistons, examining them, and removing slight marks with a hone. Measure the clearance between the cylinder bore and the pistons with a feeler gauge or a micrometer and make sure that there is not greater than 0.006 in (0.15 mm) of space. Ensure ports are clear and are not blocked to ensure that the fluid flows. Wipe everything off, coated the inside of the cylinder with new brake fluid, dipped the pistons and cups into clean brake fluid and fitted the secondary and primary cups to the pistons. Install the guide pin into the stop bolt hole, push the spring and secondary piston assembly into the cylinder, take out the guide pin but do not sacrifice pressure and put in the stop bolt and washer. The lubricated primary piston assembly and spring are then installed next and then the stop washer and stop ring. Lastly, insert the spring and check valve into the cylinder in their usual positions, and attach the joint bolt behind the check valve to a torque of 43 to 51 ft-lb (6.0 to 7.0 m-kg) and make sure the piston cups do not block the compensating ports before fitting the reservoir bushings and assembly.