Changing the brake fluid bleeding the brakes

Important Notes

Use only new DOT brake fluid. Observe change intervals and brake fluid grade. Total brake fluid quantity for fluid change: approx. 1 liter.

On vehicles up to MY '92, the brake fluid must be replaced every 2 years as a minimum.

As of MY '93, the brake fluid change interval has been increased to 3 years - along with the use of special DOT 4 brake fluid.

The 3-year change interval is valid as of MY '93, but only in conjunction with the use of the special Porsche brake fluid. The brake fluid is available under Part No. 000.043.202.04.

Container contents: 5 liters (as of May, 1992).

This special brake fluid may also be used on pre-MY '93 vehicles. However, the two-year fluid change interval will remain valid for those vehicles.

Brake fluid

The new brake fluid - Part No. 000.043.202.04 - offers superior properties. Compared to the brake fluid specified previously, its main features are further reduction of water absorption and increased wet and dry boiling points.

Notes on water absorption: Water contents of only 2 % in the brake fluid will cause the boiling point to drop by approx. 60°C.

As of MY '93, only the new brake fluid must be used when topping up the reservoir. Any mixture of former brake fluid with the new brake fluid causes the safety margin of the fluid to be narrowed down unnecessarily. Both the former and the new brake fluid are of amber color.

Sequence of operation for bleeding and brake fluid change

- Fill reservoir with new brake fluid up to the upper edge. Connect bleeding device to expansion tank. Turn bleeding device on. Bleeding pressure approx. 1,5 bar.

- Continue bleeding or changing the brake fluid, respectively, on the other brake calipers (no special sequence to be observed).

Open each bleeder valve until clear brake fluid or until the corresponding brake fluid change quantity per caliper (approx. 250 cm3) is reached, note that each four-piston fixed caliper must be bled at both bleeder valves.

Changing the brake fluid / bleeding the brakes

Printed in Germany - V, 1992

- To check that escaping brake fluid is clean and free from air bubbles, and to determine the brake fluid quantity used, use a suitable receiver bottle.

- After fitting a new brake master cylinder, depress brake pedal fully several times with the bleeder valves open during the bleeding operation. This allows trapped air to escape from the brake master cylinder.

- When changing the brake fluid, also drain some brake fluid from the clutch slave cylinder.

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

Don't pay hundreds of dollars to find out what is wrong with your car. This book is dedicated to helping the do it yourself home and independent technician understand and use OBD-II technology to diagnose and repair their own vehicles.

Get My Free Ebook


Post a comment