Oldsmobile 18013426 Cylinder,Brake Master

The removal and installation process for brake master cylinders is detailed as follows, Tag and disconnect hydraulic lines, cap lines to prevent leakage, and remove the brake master cylinder attaching nuts, then remove the brake master cylinder. For non-power brakes, disconnect the push rod from the brake pedal. To reinstall a non-power brake master cylinder, position it against the firewall with the push rod inserted, tighten attaching nuts, and attach the push rod to the brake pedal. For power brake systems, position the brake master cylinder over the push rod and tighten nuts. Install hydraulic lines and bleed the brake system. During overhaul, remove the brake master cylinder from the car, eliminate mounting gasket, boot, and main cover, drain the fluid, secure the cylinder and remove push rod retainer and secondary piston stop bolt. Compress the retaining ring, extract it with the primary piston assembly, use compressed air to force out the secondary piston, spring, and retainer. Check brass tube fitting inserts, replace if needed. Clean parts with denatured alcohol and compressed air. Replace brass tube inserts by threading brake line tube nut, then position and identify piston assemblies, place secondary seals in grooves, assemble primary and secondary seals and protector, insert assembly into cylinder, seat spring against bore, push in primary piston, snap retaining ring, replace reservoir diaphragm and cover. Overhaul of power brake master cylinders' main cylinder portion follows the same steps as for manual cylinders.

As many types and sizes of brake master cylinders were installed on the Chevelle, it may be wise to take all components to the auto parts store for proper fitting. Begin by removing the hydraulic lines at the brake master cylinder, collecting any fluid spillage with dry cloths, and plugging the ends of the hydraulic lines to prevent fluid loss or dirt from entering the system. For manual brakes, disconnect the push rod at the brake pedal inside the car. Unbolt and remove the brake master cylinder from the firewall or power booster, taking care to avoid dripping brake fluid on any painted surface, as it can ruin the finish. Drain all fluid from the brake master cylinder and place the unit in a vise, using wood blocks to cushion the jaws. For manual brakes, remove the push rod retaining ring, then take out the secondary stop bolt from the bottom of the front fluid reservoir (Delco Moraine) or from the base of the brake master cylinder body (Bendix). Remove the retaining ring from the groove and extract the primary piston assembly, followed by the secondary piston, spring, and retainer, which can be drawn out using a piece of bent stiff wire. Examine the inside surface of the brake master cylinder and the secondary piston for any scoring or 'bright' wear areas; if found, the entire brake master cylinder should be replaced. If the components are in good condition, wash them in clean hydraulic fluid, discard all rubber components and the primary piston, and purchase a rebuild kit containing all necessary parts for the overhaul. Inspect the tube seats in the brake master cylinder body where the fluid pipes connect; if damaged, replace them with new ones from the overhaul kit by threading a screw into the tube and prying outwards, then forcing the new ones into place using a spare brake line nut. Place the new secondary seals in the grooves of the secondary piston, assemble the primary seals and seal protector over the end of the secondary piston, and lubricate the cylinder bore and secondary piston with hydraulic fluid. Insert the spring retainer into the spring, then place the retainer and spring over the end of the secondary piston, ensuring the retainer locates inside the primary seal lips. With the brake master cylinder vertical, push the secondary piston into the bore to seat its spring, coat the seals of the primary piston with brake fluid, and fit it into the cylinder bore while holding it down to install the retaining ring in the cylinder groove. Continue to hold the piston down while installing the stop screw, then install the reservoir diaphragm into the reservoir cover plate, ensuring it is fully collapsed inside the recessed lid. Finally, install the brake master cylinder in the reverse order of removal, torque-tightening the attaching nuts to specifications, fill the brake master cylinder with fresh brake fluid, and bleed the brake master cylinder and complete hydraulic system.

Push in the primary piston, ensuring it's properly positioned.

Only Heavy Duty Brake Fluid meeting DOT 3 or 4 specifications should be used.

Remove the brake failure warning switch and the two proportioner valves, noting their respective positions as they are different. Place the 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. 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.

Only Heavy Duty Brake Fluid meeting DOT 3 or 4 specifications should be used.

Coat the seals of the primary piston with brake fluid and fit it into the cylinder bore, holding it down while the retaining ring is installed in the cylinder groove.

Inspect the tube seats in the master cylinder body where the fluid pipes connect; if damaged, replace them with new ones from the overhaul kit, using a screw to force them out and a spare brake line nut to install the new ones.

Purchase a master cylinder overhaul kit that includes all necessary replacement parts, particularly rubber seals, which are crucial for fluid control.

During the rebuild procedure, it is essential to avoid allowing 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.

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.