Drums and Hubs

9-inch, 10-inch, 12-inch Trailer Brake Drums

Brake drums are the primary element in the assembly of electric, mechanical and hydraulic trailer brakes.

Problems arise when electric brakes become hot. Hot brakes, worn shoes, and hot magnets are signs of wear.

Caravan Brake Drum Ratings

• 9″ Mechanical – 1450kg Max Load Capacity – 1200kg Max Braking Capacity
• 9″ Hydraulic – 1450kg Max Load Capacity – 1450kg Max Braking Capacity
• 10″ Electric – 1600kg Max Load Capacity – 1600kg Max Braking Capacity.
• 12″ Electric – 2250kg Max Load Capacity – 1250kg Max Braking Capacity.

There are three leading causes of hot brake drums:

• Worn bearings
• Worn brake shoes
• Wrong size wiring

Brake parts, including drums, must be replaced, as a result of wear.

Quite often we hear of wheel nuts coming loose on drums and hubs from caravanners on outback roads.

We discovered those caravanners who tightened their nuts every morning had no problem with broken wheel studs.

Those caravanners whose wheels nuts were falling off were suffering damaged and sheered off wheel studs.

One way to combat loose wheel nuts is to install wheel nut indicators.

The lesson learnt was, when driving on rough dirt and corrugated roads, include a wheel nut tightening check on your rig each morning.

Understanding the Calculation

The Face to Face measurements to calculate Tip to Tip measurement is as follows:

S/L 10” Electric Drum add 103mm
S/L 150mm Lazy add 100mm
10” Disk Rotor add 98mm
PLL 10” Electric Drum add 122mm
2T x 12” Electric Drum add 172mm
2T x 205mm Lazy add 172mm