For 1990-2009 cars

### Substandard or Contaminated Brake Fluid

Caution: Brake fluid may irritate eyes and skin. In case of contact, take the following actions:

• | Eye contact--rinse thoroughly with water.

• | Skin contact--wash with soap and water.

• | If ingested--consult a physician immediately.

Notice: Avoid spilling brake fluid on any of the vehicle's painted surfaces, wiring, cables or electrical connectors. Brake fluid will damage paint and electrical connections. If any fluid is spilled on the vehicle, immediately flush the area with water to minimize the potential for damage.

Important:

• | Use only Delco Supreme 11® Brake Fluid, GM P/N 1052535, or the equivalent DOT 3 brake fluid.

• | Do not use power steering or transmission fluid in the brake system.

• | Do not reuse brake fluid collected during system bleeding.

• | Always store brake fluid in a closed container. Reseal brake fluid containers immediately after use. Do not use brake fluid left in an open or improperly sealed container because it absorbs moisture or can become contaminated.

Improper brake fluid, mineral oil (i.e. power steering fluid and transmission fluid) or water in the fluid may cause the brake fluid to boil or the rubber components in the hydraulic system to deteriorate.

If the primary piston cups are swollen, then the rubber parts have deteriorated. This deterioration may be evidenced by swollen piston cups on the drum brake wheel cylinders, or a substandard or contaminated brake or master cylinder cover diaphragm.

If deterioration of rubber is evident, complete the following procedure:

1. Disassemble all of the hydraulic parts.
2. Wash the parts with alcohol.
3. Dry these parts with non-lubricated compressed air before assembly in order to keep alcohol out of the system.
4. Replace all of the rubber parts in the system, including the hoses.
5. When working on the brake mechanisms, check for fluid on the linings.
6. If too much fluid is found, replace the linings.

If the master cylinder piston seals are satisfactory, check for leakage or excessive heat conditions. If these conditions are not found, drain the fluid, flush with brake fluid, refill and bleed the system.

Flush the system if there is any doubt as to the grade of the fluid in the system or if fluid has been used which contained parts that have been subjected to contaminated fluid.

### Flushing the System

Flush the entire hydraulic system with clean brake fluid whenever new parts are installed in the hydraulic system. Approximately 0.95 liters (one quart) of fluid is required to flush the hydraulic system.

Flush the system if there is any doubt as to the grade of the fluid in the system or if fluid has been used which contains the slightest trace of petroleum based fluids. All rubber parts that have been subjected to a contaminated fluid must be replaced.

### Brake Fluid

Brake fluid must be clean and free of impurities at all times. The brake system will require flushing if any brake fluid impurities are found. Refer to Substandard or Contaminated Brake Fluid to determine the condition of the brake fluid. Refer to Hydraulic Brake System Flushing for brake system flushing procedures.