Genuine Pontiac Phoenix Brake Master Cylinder

Pontiac Phoenix Brake Master Cylinder Parts Questions & Experts Answers

• Repair Kit, Brake Mast Cyl
  18007935
  Q: How to overhaul a master cylinder for Buick Skylark,Oldsmobile Omega and Pontiac Phoenix?

  A: Before dismantling, it is advisable to purchase a Brake Master Cylinder overhaul kit that includes all the necessary replacement parts, particularly the rubber seals, to ensure proper fluid control within the Brake Master Cylinder. During the rebuild procedure, be cautious not to allow grease or mineral-based solvents to contact the rubber parts. To protect painted surfaces from brake fluid spills, cover the front fender and cowling area of the car. Start by disconnecting the electrical lead from the brake failure warning switch and then disconnect the brake line connections, using rags or newspapers to soak up the fluid that will drain out. For manual brake setups, disconnect the Brake Master Cylinder pushrod from the brake pedal inside the car. Remove the two Brake Master Cylinder mounting nuts, take out the Brake Master Cylinder from the car, and drain any remaining fluid. Remove the brake failure warning switch and the two proportioner valves, noting their respective positions as they are different. For further disassembly, it is helpful to place the Brake Master Cylinder in a vice with blocks of wood on either side to avoid overstressing the aluminum body. Use an Allen wrench to remove the switch piston plug and extract the switch piston assembly from the bore. Next, remove the primary piston retaining ring and then the primary and secondary piston assemblies. Also, remove the plastic reservoir and the quick take-up valve retaining ring, and clean all parts in denatured alcohol, avoiding gasoline or mineral-based solvents that could damage the rubber seals. Inspect the cylinder bore for any imperfections and use crocus cloth if needed, rinsing the bore with clean brake fluid afterward. Replace the old seals with new ones, lubricate the bore with brake fluid, and reassemble the primary piston assembly. Similarly, disassemble and install new 0-rings and retainers for the switch piston assembly before putting it back into the cylinder. Install new 0-rings on the proportioner valves and the failure warning switch, and insert the quick take-up valve into the cylinder body with its retaining ring. Press new reservoir grommets into the cylinder body, place the reservoir top down on a flat surface, and press the cylinder body onto it with a rocking motion. Install the cylinder on its mounting studs and reconnect the Brake Master Cylinder pushrod (for manual brake setups) and the brake line connections, torquing them to specs. Reconnect the electrical lead to the failure warning switch. Fill the Brake Master Cylinder reservoir with brake fluid and bleed the brake system. Finally, install the reservoir diaphragm and cover, and test drive the car while checking for proper braking performance and leaks.