Clutch Pedal Spongy Low Pedal Effort

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Cause	Action
DEFINITION: The clutch pedal may feel spongy, or it requires very little effort to operate. Review Symptoms - Clutch and perform the necessary inspections.
Air in the hydraulic system	Bleed the clutch hydraulic system. Refer to Hydraulic Clutch Bleeding .
Master cylinder fluid level low	Inspect for leakage in the clutch master cylinder, hose connections, and the clutch actuator. Repair or replace any faulty components.
Incomplete pedal return	Inspect the pedal for full return. Clear any obstacles that may interfere with the pedal operation. Replace the clutch pedal return spring, if equipped. Refer to Clutch Pedal Replacement . Faulty clutch start switch. Refer to Clutch Pedal Engine Start Switch Replacement .
Clutch incorrectly installed	Remove the clutch and install it correctly. Refer to Clutch Assembly Replacement .
Clutch mounting bolts loose or broken	Remove the broken bolts. Replace the broken or loose bolts and tighten. Refer to Clutch Assembly Replacement .
Release bearing worn or damaged	Replace the release bearing. Refer to Clutch Actuator Cylinder Replacement (NV3500/NV4500 Transmissions) or Clutch Actuator Cylinder Replacement (ZF S6-650 Transmission) .
Contaminated hydraulic fluid	Inspect the clutch hydraulic fluid for contamination of water. If available, use a brake fluid boiling point tester. Boiling point should be above 177°C (350°F). Inspect the reservoir cap for being faulty if water is present. Inspect the clutch hydraulic fluid for dirt or debris. Flush and bleed the clutch hydraulic system if the above conditions are found. Refer to Hydraulic Clutch Bleeding . If mineral oil was added, replace the clutch master cylinder and clutch actuator cylinder due to seal damage. Refer to Clutch Master Cylinder Replacement and Clutch Actuator Cylinder Replacement (NV3500/NV4500 Transmissions) or Clutch Actuator Cylinder Replacement (ZF S6-650 Transmission) .