J&M 375ST - Manual (Page 23)

20
2.0 Service 2.0 Service
How to adjust electric brakes:
1. Park the Speed Tender on firm and level ground.
2. Block the trailer tires on the opposite side securely so that no forward or rearward movement is possible.
3. Jack up the Speed Tender.
4. Secure the trailer on jack stands of adequate capacity front and rear.
5. At the back of the wheel, on the brake backing plate, there is a small rubber plug near the bottom of the
backing plate. Pry out this plug to give access to the star wheel adjuster.
6. Insert the brake adjuster tool and maneuver it so that the tool engages with the teeth in the star wheel.
The star wheel looks like a gear with exposed teeth on the perimeter.
7. Turn the adjuster until the brake locks up (you can no longer rotate the wheel by hand). This centers the
brake shoes on the brake drum so that they are in the correct position.
8. Now back off the star wheel 8 to 10 clicks or as specified by the manufacturer. The wheel should spin
freely with no apparent drag to slow it down. A slight scraping noise is normal as the wheel turns.
9. Repeat this procedure for all the wheels
When to adjust brakes:
1. After the first 200 miles of operating when the brake shoes and drums have “seated.”
2. At 3,000 mile intervals or once a year, whichever comes first.
Brake Cleaning and Inspection:
Your Speed Tender brakes must be inspected and serviced at yearly intervals, (or more often as use and perfor-
mance requires). Magnets and shoes must be changed when they become worn or scored thereby preventing
adequate vehicle braking. Clean the backing plate, magnet arm, magnet, and brake shoes. Make certain that all
the parts removed are replaced in the same brake and drum assembly. Inspect the magnet arm for any loose or
worn parts. Check shoe return springs, hold down springs, and adjuster springs for stretch or deformation and
replace if required.
Brake Shoe and Lining Inspection:
A simple visual inspection of your brake linings will tell if they are usable. Replacement is necessary if the lin-
ing is worn (to within 1/16” or less), contaminated with grease or oil, or abnormally scored or gouged. Hairline
heat cracks are normal in bonded linings and should not be cause for concern (Figure 2.6). When replacement
is necessary, it is important to replace both shoes on each brake and both brakes of the same axle. This will help
retain the “balance” of your brakes.
Figure 2.6
Acceptable
Hairline Cracks