Multiquip MQ POWER WHISPERWATT SERIES 60HZ GENERATOR (STD.) (KOMATSU SAA6D170E-3 DIESEL ENGINE) DCA800SSK2 - Manual (Page 43)

DCA800SSK2 60 HZ GENERATOR • OPERATION AND PARTS MANUAL — REV. #0 (09/03/09) — PAGE 43
TRAILER MAINTENANCE
ELECTRIC BRAKES
Electrically actuated brakes (Figure 66) are similar
tohydraulic brakes. the basic difference is that hydraulic
brakes are actuated by an electromagnet. listed below are
some of the advantages that electric brakes have over
hydraulic brakes:
Brake system can be manually adjusted to provide the

corrected braking capability for varying road and load
conditions.
Brake system can be modulated to provide more or less 
braking force, thus easing the brake load on the towing
vehicle.
Brake system has very little lag time between the time 
the vehicle’s brakes are actuated and the trailer’s brakes
are actuated.
Brake system can provide an independent emergency

brake system.
Remember in order to properly synchronize the tow vehicle’s
braking to the trailer’s braking, can only be accomplished
by road testing. Brake lockup, grabbiness or harshness is
due to lack of synchronization between the tow vehicle and
the trailer being towed or underadjusted brakes.
Before any brake synchronizations adjustments can be
made, the trailer brakes should be burnishedin by applying
the brakes 2030 times with approximately a 20 m.p.h.
decrease in speed, e.g. 40 m.p.h. to 20 m.p.h. Allow ample
time for brakes to cool between application. This allows
the brake shoes to slightly be seated into the brake drum
surface.
Figure 66. displays the major electric brake components
that will require inspection and maintenance. Please
inspect these components as required. See Table 13.
Electric Brake Troubleshooting.
Magnets For All Electric Brakes
To make certain an electricallyoperated braking system
will function properly, you must have your dealer inspect
the magnets at least once a year, or each 12,000 miles.
See the brake manual for wear and current inspection
instructions.
Brake Controller
The electric brake controller is part of the tow vehicle and
is essential in the operation of the electric brakes on the
trailer. The brake controller is not the same
as the safety
breakaway brake system that may be equipped on
the trailer.
.
Hydraulic Brake Components Figure 66.
Brake Drums (or discs), Linings, and Hoses
Brake drums or discs must not have cracks longer than one
half the width of the friction area. Linings must not be loose,
soaked with oil or grease or be dangerously thin. Mechanical
parts must be in place, not broken or missing. Check that all air
hoses connected to the brake chambers are not worn or cut
due to rubbing
.
Air Leaks
Always check for brake air leaks before towing the trailer.
NEVER tow the trailer with an brake air leak problem. The
possibility exists of brake failure.
Electric Brake Troubleshooting Table 13.
Symptom Possible Cause Solution
No Brakes or Intermittent Brakes
Any open circuits or broken wires? Find and correct.
Any short circuits? Find and correct.
Faulty controller? Test and correct.
Any loose connections? Find and repair.
Ground wire secure? Find and secure.
Weak Brakes or Brakes Pull to
One Side
Grease or oil on magnets or
linings?
Clean or replace.
Connections corroded?
Clean and correct cause of
corrosion.
Brake drums scored or grooved? Machine or replace.
Brakes synchronized? Correct.
Locking Brakes
Brake components loose, bent or
broken?
Replace components.
Brake drums outofround? Replace.
Noisy Brakes
System lubricated? Lubricate.
Brake components correct? Replace and correct.
Dragging Brakes Bearings of the wheel adjusted? Adjust.