Multiquip DCA-800SSK Air Brake System, S-Cam Brakes, Brake Drums or discs, Linings, and Hoses

DCA-800SSK — MAINTENANCE

Brakes

Trailer brakes should be inspected the first 200 miles of operation. This will allow the brake shoes and drums to seat properly. After the first 200 mile interval, inspect the brakes every 3,000 miles. If driving over rough terrain, inspect the brakes more frequently.

Air Brake System

Air brakes use compressed air to make the brakes function. Air brakes are a good and safe way of stopping large and heavy vehicles. There are many components that make up an air-brake system, such as the air compressor, air compressor governor, air storage tanks and air tank drains. These components need to be maintained by qualified and trained technicians.

S-Cam Brakes
When the brake pedal is pushed, air is let into each brake	Figure 76. Hydraulic Brake Components
chamber (Figure 76). Air Pressure pushes the rod out, moving
the slack adjuster, thus twisting the brake cam shaft. This	Brake Drums (or discs), Linings, and Hoses
turns the s-cam (so called because it is shaped like the	Brake drums or discs must not have cracks longer than one
letter "S").
	half the width of the friction area. Linings must not be loose,
The s-cam forces the brake shoes away from one another
	soaked with oil or grease or be dangerously thin. Mechanical
and presses them against the inside of the brake drum.When	parts must be in place, not broken or missing. Check that
the brake pedal has been released, the s-cam rotates back	all air hoses connected to the brake chambers are not worn
and a spring pulls the brake shoes away from the drum,	or cut due to rubbing.
letting the wheels roll freely.	Air Leaks
Air Tank Drains
	Always check for brake air leaks before towing the trailer.
Compressed air usually has some water in it which is bad
	NEVER tow the trailer with an brake air leak problem. The
for the air brake system. Water can freeze in cold weather	possibility exists of brake failure.
and thus cause brake failure. The water tends to collect in
the bottom of the air tank. Daily air tank drainage is required

to remove water from the air tank.
			Table 15. Air Brake Troubleshooting
		Symptom		Possible Cause	Solution
				Air Brake line broken or kinked?	Repair or replace.
		No Brakes		Worn lining?	Replace lining.
				Slack adjustment incorrect?	Adjust correctly.
	Use Table 15 as a basic			Brake lining glazed?	Reburnish or replace.
				Trailer overloaded?	Correct weight.
NOTE	troubleshooting guide when
		Weak Brakes or Brakes Pull to
				Brake drums scored or grooved?	Machine or replace.
	brake problems occur.	One Side
				Tire pressure correct?	Inflate all tires equally.
				Tires unmatched on the same axle?	Match tires.
		Locking Brakes		Brake components loose, bent or broken?	Replace components.
				Brake drums out-of-round?	Replace.
				Brake lining glazed?	Replace brake lining.
		Noisy Brakes		Drums and lining glazed?	Replace brake lining and
					drum.
				Brake lining thickness incorrect or not	Install new shoes and linings.
		Dragging Brakes		adjusted correctly?
				Zerk fittings lubricated?	Lubricate zerk fittings.

PAGE 56 — DCA-800SSK (STD) — OPERATION AND PARTS MANUAL — REV. #4 (06/03/10)