Lippert Components Trailer Axle (8-12K) User Manual
Page 5
Rev: 04.18.2014
Page 5
Trailer Axle 8-12K Owners Manual FULL
Break-in Period for Electric Drum Brakes
The break-in period is a typical phenomenon with drum brakes and especially electric drum brakes. Electric
drum brakes will require a break-in period to achieve full performance. This break-in period applies for new
axles and any time new brake shoes and/or magnets are installed as part of regular maintenance.
Lippert Components has found through extensive brake testing that the break-in period for our drum
brakes can range from 20 to 50 brake applications.
Brakes can be seated in by applying approximately 8-10 volts to the trailer brakes at an initial speed of 40
mph and allowing the truck/trailer combination to slow down to 20 or 25 mph. For best results do not use
truck brakes during this procedure. The trailer brakes will seat in faster by using them to stop both the truck
and trailer. The easiest method is to apply the trailer brakes using the manual activation lever located on the
in-cab brake controller. Care must be taken to not overheat the lining material, therefore brake applications
conducted at one-mile intervals will suffice. The driver should feel a noticeable difference in the brake
performance during this period, sometimes in as few as 10 applications. After 50 applications, the brake
lining material will be fully cured from the heat and develop close to 100% contact with the brake drum
surface.
This break-in period not only seats the shoe lining material but also seats in the brake electromagnets.
During the break-in period, the linings will wear at a faster rate than they do after they are seated in.
NOTE: Brakes should be manually adjusted after the first 200 miles of operation and periodically thereafter,
approx. 3,000 mile intervals.
Hubs/Drums/Bearings
Hub Removal
To remove the hub assembly for inspection, maintenance or service, follow the six (6) steps below:
Lift unit by the frame and never the axle or suspension. Do not go under unit unless it is properly
supported by jack stands. Unsupported units can fall causing death or serious injury.
1. Lift trailer and support it per manufacturer’s requirements.
2. Remove the wheel.
3. Remove the grease cap by prying the edge out of the hub. If equipped with oil lubrication, unscrew oil
cap using a 2 1/4" socket (8K) or 21/2” socket (10-12K). Let oil drain into pan.
4. Pull the cotter pin from the castle nut and remove the outer spindle nut.
5. Remove the spindle washer.
6. Pull the hub off the spindle. Do not let the outer bearing cone fall free of the assembly. The inner
bearing cone will be contained by the seal and will not fall out.
NOTE: Brakes may need to be adjusted or backed off to remove drum from spindle.
NOTE: A gear puller may be necessary to remove hub from spindle.