Instructions for filling the Buick Reatta master cylinder:
The hydraulic accumulator must be depressurized before filling the reservoir
To depressurize the accumulator, pump the brake pedal at least 25 times, with the ignition key off. You will feel a change in the pedal when the pressure is relieved. Continue pumping the pedal a few more times to ensure the pressure is removed. Leave the key off until you have filled the reservoir.Inspect the fluid level in the reservoir. The fluid level should be even with top of the arrow on the side of the reservoir.
If fluid needs to be added, clean around the cap before removing. Add enough DOT-3 brake fluid to bring the level up to the top of the arrow (full mark). DO NOT overfill!
When you turn on the ignition key, the pump on the master cylinder will run and the fluid level in the reservoir will be drawn down below the full mark. This is normal operation of the brake system. DO NOT add more brake fluid without depressurizing the accumulator.
Thanks to members of the Reatta forums for this information.
