Brake Fluid Replacement and Bleeding

Overview

This procedure replaces the brake fluid in your Porsche 944 (16v engine variants) and bleeds the brake system to remove air and old fluid. Brake fluid absorbs moisture over time, which can reduce braking performance by creating steam voids during hard braking or corroding internal components. Regular replacement—annually, or more often if you track your car—ensures safe and reliable braking.

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Tools Required

• Jack stands or ramps
• Container to catch fluid during bleeding
• Turkey baster or hand vacuum pump brake bleeder (vacuum pump required for one-person bleeding)
• Wrench (size depends on bleeder screw, typically 8mm (5/16 inch) or 10mm (3/8 inch))
• Catch rags

Parts Required

• Brake fluid (DOT 4, 1 liter or 1 quart for a complete change, e.g., ATE Super Blue 706202 for high-temperature use)

Step-by-Step Procedure

Step 1: Prepare the Vehicle

1. Place the Porsche 944 on jack stands or ramps to access all four brake calipers safely.

Step 2: Empty the Brake Fluid Reservoir

2. Remove the brake fluid reservoir cover, located near the firewall on the driver’s side of the engine bay.
3. Use a turkey baster or hand vacuum pump to remove as much old brake fluid from the reservoir as possible.
4. Wipe out the reservoir with clean rags, ensuring no dirt or debris falls inside.

Step 3: Refill the Reservoir

5. Fill the reservoir with fresh DOT 4 brake fluid (e.g., ATE Super Blue 706202) up to the “MAX” line.

Step 4: Bleed the Brakes (Two-Person Method)

6. Start with the right rear caliper (farthest from the master cylinder), then move to the left rear, right front, and left front.
7. Place a catch pan and rags under the caliper. Remove the rubber boot from the first bleeder screw (the 944 has two bleeders per caliper).
8. Select the correct wrench size (typically 8mm (5/16 inch) or 10mm (3/8 inch)) for the bleeder screw.
9. Have one person sit in the driver’s seat to pump the brake pedal several times, then hold it down firmly.
10. Open the first bleeder screw to let fluid escape into the catch pan. The pedal will sink to the floor—normal during this step. Keep it pressed until the bleeder is closed.
11. Close the bleeder screw when fluid stops flowing, then tell the person to release the pedal.
12. Repeat steps 9-11 until clean fluid flows from the bleeder (no bubbles or discoloration).
13. Move to the second bleeder on the same caliper and repeat steps 9-12.
14. Wipe up any spilled fluid with rags immediately to avoid damaging paint or components.
15. Repeat steps 7-14 for the remaining calipers in order: left rear, right front, left front.

Step 5: Bleed the Brakes (One-Person Method with Vacuum Pump)

16. Start with the right rear caliper, then proceed to left rear, right front, and left front.
17. Place the vacuum pump, catch rags, and a wrench (typically 8mm (5/16 inch) or 10mm (3/8 inch)) at the caliper. Remove the rubber boot from the first bleeder screw.
18. Attach the vacuum pump to the bleeder screw using an adapter for a tight seal.
19. Pump the vacuum pump about 10 times, then open the bleeder screw to draw fluid into the container.
20. Keep pumping until clean fluid flows out (no bubbles or discoloration).
21. If the container fills before clean fluid appears, close the bleeder, empty the container, and resume bleeding.
22. Close the bleeder screw once clean fluid flows, then move to the second bleeder on the same caliper and repeat steps 19-21.
23. Wipe up any spilled fluid with rags.
24. Repeat steps 17-23 for the remaining calipers in order: left rear, right front, left front.

Step 6: Bleed the Clutch (If Applicable)

25. If your Porsche 944 has a hydraulic clutch, bleed the clutch slave cylinder (near the transmission) using the same method (two-person or vacuum pump) as the brakes.

Post Procedure Checklist

• Check the brake fluid level in the reservoir and top off to the “MAX” line if needed.
• Inspect all calipers and the clutch slave cylinder (if applicable) for leaks.
• Press the brake pedal to ensure it feels firm, not spongy.
• Test drive the car for 5 miles (8 km) at low speed to confirm proper brake response.

Sources

• Clark’s Garage
• Pelican Parts
• Porsche 944 Workshop Manual, Volume 1
• Youtube