OEM Cadillac STS Brake Master Cylinder

Cadillac STS Brake Master Cylinder Parts and Q&A

• Master Cylinder
  19209197
  Q: How to overhaul the brake master cylinder on Cadillac STS?

  A:

  Start Brake Master Cylinder overhauls by taking out the unit from your vehicle and placing the mounting flange in a bench vise to access the rear of the primary Piston. First clean the cylinder reservoir exterior and remove its cap then diaphragm for examination. Check for damage on both parts including cuts, cracks, chips and misshapen areas. Replace any defective components. Tools allows the removal of the primary Piston assembly when you push the Piston down using a smooth tool. Using filtered low-pressure air pipe the rear outlet port of the cylinder while plugging its inlet ports. Use the clean denatured alcohol on the master cylinder outside and inside surfaces plus secondary Piston and return spring. Then check for damage signs like corrosion before reinstalling with a new part if needed. Use filtered air to dry these parts and apply delco supreme 11 brake fluid (GM P/N 12377967, Canadian P/N 992667) or its equivalent dot-3 approved brake fluid as lubricant for the master cylinder bore and all components. Insert the new primary seal elements including their retainers into the secondary Piston while adding the secondary seal. Next add the lubricated return spring and secondary Piston assembly into the cylinder bore followed by the new primary Piston assembly. Use a smooth rounded tool to push down the new Piston retainer in place before reinstalling the master cylinder reservoir parts and putting the unit back into the vehicle.
• Master Cylinder
  22797527
  Q: How to replace the brake master cylinder on Cadillac STS?

  A:

  To replace the Brake Master Cylinder, you must first check that the engine is off and exhaust the power that vacuum Brake Booster vacuum reserve has by pushing and pulling the brake pedal several times. Remove the brake fluid level indicator switch electrical connector, as well as the master cylinder primary brakes pipe fitting removing the master cylinder and then filling the fitting capping it and plugging the master cylinder outlet to prevent fluid loss and contamination. Following this, disengage the master cylinder secondary brake pipe fitting in the same way. Untighten the master cylinder nuts and remove the master cylinder from the power vacuum Brake Booster, checking for damage of the seal and replace if necessary. In the installation, the master cylinder should be placed to power vacuum Brake Booster seal in the manner it is not deformed against the body of master cylinder. It is also not adverse to bench bleed the master cylinder if a new one is installed prior to connecting it to the power vacuum Brake Booster. Hold the master cylinder nuts and tighten them with a torque of 25 nm (18 lb ft). Use the torque poll technique to tighten the master cylinder secondary brake pipe fitting to 36 nm (27 lb ft) followed by the primary brake pipe fitting to the same specification. Finally, reconnect the electrification cable to the brake fluid level indicator switch and bleed the hydraulic brake system.