TL;DR

Brake fade with a spongy pedal means fluid contamination or worn pads. Check brake fluid for water contamination first (boiling point drops sharply with water content), then measure pad thickness.

What you might see

longer stopping distance than before
pedal goes to the floor before braking
burning smell from wheel end after heavy use
brake pedal feels spongy

Likely causes

Tap to mark as ruled out

Brake pads or shoes worn below minimum thickness, reducing stopping torque
Brake fluid contaminated with water, reducing the boiling point and causing vapor lock under sustained braking
Brake drum or rotor scored beyond the service limit
Brake adjuster seized, allowing excessive pad-to-drum clearance

Required tools

Vernier calipers or brake pad thickness gauge
Drum micrometer
Brake fluid moisture test strip
Brake bleeding kit
LOTO kit
Wheel chocks

Safety first

Do not operate a forklift with brake fade. It is an immediate out-of-service condition.
Brake dust may contain hazardous materials. Use a dedicated brake cleaner spray; do not blow out drums with compressed air.

Procedure

7 steps · ~60 min

1
Lock out the forklift and chock all wheels.
2
Remove the wheel and drum. Measure pad or shoe thickness. The Toyota 8FGU minimum thickness is typically 2 mm bonded lining. Replace at or below minimum.[1]
3
Measure drum inside diameter. If the drum is more than 1 mm above the nominal diameter or shows deep scoring, it must be resurfaced or replaced.[1]
4
Test the brake fluid with a moisture test strip or a refractometer if available. Fluid with more than 3% water content must be flushed and replaced with fresh DOT-specified fluid.
5
Check the brake adjusters. Manual adjustment stars should rotate freely. Apply penetrating oil to seized adjusters; replace if they cannot be freed.
6
Reassemble the brakes and adjust the drum-to-shoe clearance to the Toyota specification before bleeding.
7
Bleed all four corners of the brake system to remove air. Start at the wheel furthest from the master cylinder.

Sources

Toyota 8-Series Forklift Operator and Maintenance Manual, Toyota Material Handling
Toyota 8FGU Series Forklift Service Manual, brake inspection and adjustment procedures (general)
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