Hino 600, Workshop Manual, Page: 365 / 451

SERVICE BRAKE (FULL AIR BRAKE) BR02–87
DIAGNOSTICS
EN0680202F300002
Symptom Possible Causes Corrective Actions
Adjusted stroke is too long.
No adjustment. The slack adjuster part number is
incorrect.
Check with WD or OEM.
The clevis angle is incorrect.
Use correct template or BSAP setting
to install clevis correctly.
Excessive wear exists between the
clevis and collar (more than 0.060"
[1.52 mm]).
Replace with threaded clevis.
The jam nut at the clevis is loose. Tighten to specification.
There is a worn clevis pin bushing in
slack arm (ID larger than 0.53" [13.46
mm]).
Replace bushing.
There is a weak or damaged air
chamber spring. Spring force must
be at least 32 lb (142.4 N) at first push
rod movement.
Replace return spring or air chamber.
The spring brake does not retract
fully.
Repair or replace spring brake.
There are worn or damaged teeth on
the pawl or actuator.
Replace pawl or actuator.
High torque is required to rotate
worm when slack is removed from
vehicle.
In service slack maximum worm
torque: 45 lb-in (5.09 N

m)
New or rebuilt slack maximum worm
torque: 25 lb-in (2.83 N

m)
Rebuild or replace slack adjuster.
Excessive looseness exists between
the splines of the camshaft and the
slack adjuster gear.
Replace powershaft, gear or auto-
matic slack adjuster as needed.
A cam brake has worn components
(cam bushing, for example).
Replace components.
Adjusted stroke is too short.
Linings drag. OEM replacement linings are not
installed.
Linings exhibit excessive swell or
growth.
Use Meritor-approved linings.
The slack adjuster part number is
incorrect.
Check with WD or OEM.
The clevis angle is incorrect.
Use correct template to install clevis
correctly.
The jam nut at the clevis is loose. Tighten to specification.
The spring brake does not retract
fully.
Repair or replace spring brake.
The manual adjustment is incorrect. Adjust brake.
Poor contact exists between the lin-
ings and the drum. The drum is out-
of-round.
Repair or replace drums or linings.
Brake temperature is not even. Correct brake balance.