Document gD6bo9Xx9ayzjdQ0BOMm3Re1e

LESSON ONE-MODULE 1 BRAKE SYSTEM DIAGNOSIS AND TESTING Brake Pedal Low or Feels Spongy A brake pedal is considered to be spongy when the pedal does not provide a firm, even feel as the driver applies the brakes. A spongy brake pedal may be caused by: Low brake fluid level. External brake system leaks. Air in the hydraulic system. Improperly adjusted rear drum brakes. Loose axle hub retainer nut. Overheated brakes. Brake Pedal Low or Feels Spongy Diagnosis To find the source of a spongy brake pedal, perform the following tests: Check the brake fluid level in the master cylinder. - If the fluid level is low, check for brake system leaks and for leaks in the master cylinder reservoir sealing points. Check for external leaks in the hydraulic system. Check for a clogged filler cap(s) vent hole(s). - If vent(s) are clogged, clean and open them as necessary. Check rear brake adjustment and adjust as necessary. Check the axle hub retainer nut. - If loose, inspect the bearing for damage, replace the hub retainer nut and tighten to specification. Bleed the brake system. 12 September, 2005 Brake System Diagnosis and Repair