Brake pedal goes too low and brakes not working properly

Hi,

Have you checked to make sure the brake fluid level is full? Also, does this truck have rear drum brakes? I ask because if they are out of adjustment, the pedal will travel further than it should. However, if you pump them, it should get back to a normal travel distance.

Here are the directions for adjusting the rear brakes if they are the drum type:

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1999 GMC Truck K Yukon/Denali 4WD V8-5.7L VIN R
Drum Brake Adjustment (Leading/Trailing Drum Brakes)
Vehicle Brakes and Traction Control Drum Brake System Adjustments Drum Brake Adjustment (Leading/Trailing Drum Brakes)
DRUM BRAKE ADJUSTMENT (LEADING/TRAILING DRUM BRAKES)
A manual adjustment of the rear drum brakes is required after replacing the rear linings.

1. Remove the lanced area in the backing plate.
2. Turn the adjusting screw until the wheel can just be turned by hand.
3. The brake drag should be equal at both wheels.
4. Back off the adjusting screw 20 notches. Brakes should have no drag after the adjusting screw is backed off about 10 notches. If a heavy drag is still present, refer to Park Brake Cable Service/Adjustment (All Except C350OHD).
5. Install an adjusting hole cover in the backing plate.
6. Check the parking brake adjustment.

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Let me know if that helps or if you have other questions.


Take care,
Joe