Buick 18060114 Cylinder Asm,Brake Master

Use only Heavy Duty Brake Fluid meeting DOT 3 or 4 specifications. Do NOT use any other fluid or severe brake system damage may result. The Brake Master Cylinder is located under the hood, in the left rear section of the engine compartment. It is divided into two sections (reservoirs) and the fluid must be kept within ¼ in. (6mm) of the top edge of both reservoirs. The level should be checked at least every 7,500 miles (12,000 km). To check the fluid level, simply pry off the retaining bail and then lift off the top cover of the Brake Master Cylinder. Be careful not to spill any brake fluid on painted surfaces, as brake fluid eats paint. Do not allow the brake fluid container or the Brake Master Cylinder reservoir to remain open any longer than necessary; brake fluid absorbs moisture from the air, reducing the effectiveness and causing corrosion in the lines. The reservoir cover on some models (1978 and later) may not have a retaining bail. If so, simply pry off the cover with your fingers.

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.

They should be reassembled with new seals.