Troubleshooting Troubleshooting – Brakes Estimated reading: 4 minutes Contributors Overview This troubleshooting guide is designed to help diagnose and resolve brake system issues specific to the 16v engine Porsche 944 S / S2 (1989–1991). Proper brake function is critical for vehicle safety and performance, especially given the S / S2’s high-performance characteristics and late-model alloy control arms, which differ from earlier 944 models. The guide addresses common brake-related symptoms, their possible causes, checks, and recommended procedures, ensuring your S / S2 maintains optimal braking performance. Pink and blue text represents links to additional resources, tools, parts, and partner websites. Brake Pedal Goes to Floor When Depressed Possible Causes Checks Procedure Brake fluid is low. Check brake reservoir level and fill if necessary with DOT 4 brake fluid, standard for the 3.0L S / S2. N/A Brake Master Cylinder bad. Check for signs of leakage from the Master Cylinder in the engine compartment near the firewall and inside the driver’s footwell. If leakage is present or other causes are ruled out, replace the Master Cylinder. Refer to Porsche 944 Workshop Manual for Master Cylinder replacement (BRAKE-06). Air in the brake system. Bleed brakes to remove air, ensuring proper brake pedal feel. Refer to Porsche 944 Workshop Manual for brake bleeding procedure (BRAKE-01). Brake Pedal Feels Spongy During Braking Possible Causes Checks Procedure Master Cylinder Mounting bolts loose. Check bolts securing the Master Cylinder and tighten if necessary. N/A Brake Master Cylinder bad. Check for signs of leakage from the Master Cylinder in the engine compartment near the firewall and inside the driver’s footwell. If leakage is present or other causes are ruled out, replace the Master Cylinder. Refer to Porsche 944 Workshop Manual for Master Cylinder replacement (BRAKE-06). Air in the brake system. Bleed brakes to remove air, ensuring proper brake pedal feel. Refer to Porsche 944 Workshop Manual for brake bleeding procedure (BRAKE-01). High Pitched Squeal During Braking Possible Causes Checks Procedure Brake pads worn. Inspect brake pads for wear and replace immediately if worn beyond the minimum thickness specified for the S / S2. Refer to Porsche 944 Workshop Manual for brake pad replacement (BRAKE-02). High Pitched Squeal During Driving – Goes Away During Braking Possible Causes Checks Procedure Excessive Brake Dust. Check for brake dust accumulation between the brake pad and caliper piston, which can cause vibration and squealing during driving. Anti-Squeal Pads: Use anti-squeal pads, included with most S / S2-compatible brake pad sets or available at auto parts stores. Brake Pad Grease: Apply brake pad grease to the back of the brake pad to reduce vibration. Use high-temperature brake grease or bearing grease. Adhesive: Apply 3M Vinyl and Trim Adhesive to the back of the brake pad to adhere it to the caliper piston, stopping vibration. Brake Pads: Switch to low-dust brake pads compatible with the S / S2 to reduce dust buildup. Refer to Porsche 944 Workshop Manual for brake pad replacement (BRAKE-02). Vehicle Pulls to One Side During Braking Possible Causes Checks Procedure Wrong Tire Pressure. Check that all tires have the correct pressure as specified in the S / S2 owner’s manual. N/A Suspension Out of Alignment. Inspect the S / S2’s alloy control arms and have alignment checked and corrected by a professional, as misalignment can affect braking. N/A Crimped or Pinched Brake Line. Inspect all brake lines for damage or restrictions. N/A Loose or Malfunctioning Brake Caliper. Raise wheels off the ground, apply brakes, and attempt to turn wheels by hand. If a caliper is malfunctioning, bleed the brake for that wheel to check for a clogged line. If the line is clear, the caliper may need replacement or rebuilding. Refer to Porsche 944 Workshop Manual for caliper service procedures. Pulsations or Jerky Braking Possible Causes Checks Procedure Brake rotor lateral runout bad. Check rotor lateral runout using a dial indicator, ensuring it is within specs for the S / S2. Refer to Porsche 944 Workshop Manual for rotor inspection and replacement (BRAKE-04). Brake pads contaminated. Inspect brake pads for contamination with brake fluid or oil, which can cause jerky braking. Remove and check pads, replacing if necessary. Refer to Porsche 944 Workshop Manual for brake pad replacement (BRAKE-02). Sources Clark’s Garage Pelican Parts Porsche 944 Workshop Manuals YouTube Tagged:Brakes Troubleshooting Troubleshooting – Brakes - PreviousTroubleshooting – Automatic TransmissionNext - Troubleshooting – BrakesTroubleshooting – Clutch
