Problem #13

Slow or No Release of Brakes

POSSIBLE CAUSES
Hinge Pin on Brake Pedal
Air Delivery Lines restricted
Control Line restricted (Delivery of Brake (Foot) Valve to Service Port of Relay restricted)
Relay Valve not exhausting
Quick Release Valve not exhausting
Brake (Foot) Valve not exhausting
Binding parts in the Foundation Brake
Step #1

Check Hinge Pin in Brake Pedal. If free, go to Step #2.
Step #2

Have an assistant make a brake application and release.
Listen for exhaust noise from the exhaust ports of: Relay Valve
Quick Release Valve
Brake (Foot) Valve If there are no exhaust noises, go to Step #3.
If exhaust is normal, go to Step #4.

Step #3

Check for restrictions in all Delivery Lines from the Valve that is not exhausting. If a kink or dent is not found, remove and check internally.

NOTES:

Line could be plugged or may have been crimped with vice grips or pliers.
If line is free of restrictions, replace or repair valve.

Step #4

Check S-Cam. It should rotate freely (Cam Brakes).
Check Anchor-Pins (Cam Brakes).
Check Wedge Assembly and Actuation Housing (Wedge Brakes).
Check Clevis Pin in Slack Adjuster. It should rotate freely (Cam Brakes).

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