Multiquip operation manual DCA-600SSV -TRAILER Brakes Maintenance

DCA-600SSV —TRAILER BRAKES MAINTENANCE

Electric Brakes

Electrically actuated brakes (Figure 72) are similar to hydraulic 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 under-adjusted brakes.

Before any brake synchronizations adjustments can be made, the trailer brakes should be burnished-in by applying the brakes 20-30 times with approximately a 20 m.p.h. de- crease 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 sur- face.

Figure 72. displays the major electric brake components that will require inspection and maintenance. Please inspect these components as required. See Table 15. Electric Brake Troubleshooting.

Magnets For All Electric Brakes

To make certain an electrically-operated 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 instruc- tions.

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.

Figure 72. Electric Brake Components

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.

Table 15. Electric Brake Troubleshooting

Symptom	Possible Cause	Solution
No Brakes or Intermittent	Any open circuits or broken wires?	Find and correct.
Brakes
	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	Grease or oil on magnets or linings?	Clean or replace.
One Side
	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 out-of-round?	Replace.
Noisy Brakes	System lubricated?	Lubricate.
	Brake components correct?	Replace and correct.
Dragging Brakes	Bearings of the wheel adjusted?	Adjust.

PAGE 48 — DCA-600SSV — OPERATION AND PARTS MANUAL — REV. #0 (07/13/09)