KNOW YOUR WEIGHTS
- Aggregate Trailer Mass (ATM) of your caravan permitted by the manufacturer. This relates to the total travelling weight, including payload, such as water, gas, food and luggage and is usually stamped on a plate to the A-frame.
- Tow ball weight of your fully loaded caravan. This is the weight on the back of your car (or on the jockey wheel if the van is uncoupled). You can measure this on a public weighbridge.
USE A WEIGHT DISTRIBUTION HITCH (WDH)
- Where the tow ball weight exceeds 150kg, it is generally recommended that you use a heavy-duty weight distributing hitch. When fitted correctly, this will ensure that your tow vehicle stays level when hitched and will allow its front brakes to do their job in pulling it up.
- When fitting a WDH, it is important to ensure your ball weight does not fall below 10 per cent of the total caravan weight to prevent sway issues that will further impact on its stability and braking ability.
SELECT AN APPROPRIATE TOW CAR
- Now that you know the caravan ATM and tow ball weight, you need to look at the specifications for your potential tow vehicle: the tare (TARE) weight it is built to tow; the gross vehicle mass (GVM); the gross combination mass (GCM); its tow rating and the ball weight rating.
- The caravan’s ball weight should be less than the tow vehicle’s maximum ball weight rating, and the caravan’s ATM should be less than the tow vehicles maximum tow rating. Add the trailer ATM to the tow vehicles GVM, and the combined weight should be less than the GCM. If the total of the ATM and GVM is higher than the GCM, you may still be able to tow the caravan if you don’t load the caravan and tow vehicle to their permitted maximum.
INSTALL AN ELECTRONIC BRAKE CONTROLLER
- Unless you have overrun brakes fitted (vehicles under 2.0t), an in cab brake controller that facilitates the manual operation of the caravan/ trailers brakes is mandatory for any trailer that weighs more than 750kg and your caravan’s brakes will not work without one. (Refer to VSB1 for the specific braking requirements that apply to your combination)
- This device can be attached under, or in the dash of your vehicle, or sometimes in the centre console. It is wired to the car’s battery, the stop light circuit and also to the seven or 12-pin socket into which the caravan plug connects. Its installation is virtually independent of the vehicle’s electrical circuit and has no conflict with car computers or ABS Braking Systems. Installation usually takes around three to four hours depending upon the vehicle.
- There are a number of different brands of controllers on the market, but all operate on similar principles. Power is fed from the vehicles stoplights into the controller then back to the caravan through the plug and socket. This allows the caravan brakes to come on automatically when you apply the vehicle brakes. The characteristics of the power flow will vary from unit to unit.
- Whatever unit you have fitted, try it out on a quiet road before you set out on a trip and if the caravan wheels start to lock, slacken off the current until you can feel an even ‘tug’ when you brake your rig. This optimum setting will vary from stop-start town traffic to freeway use and from first thing in the morning, when your caravan’s brakes are cold, to later in the morning, when they have warmed up. Be prepared to change the setting from time to time depending on the conditions.
- It is recommended to have your caravan serviced every 12 months, even if it hasn’t travelled far. Brake seals can perish over time and rust, if you have previously towed through fresh, or even worse, salt water, can do a lot of hidden damage.
- Brake linings and the electric magnets that operate them can also wear out and we know of some off-road caravans that need new brake pads every 12 months.
- Wheel alignment can change and chop out your tyres if you nudge a few kerbs, while tyre sidewalls deteriorate due to standing around all day in the sun, wind, rain and cold.
- Take a look at the tyre sidewall ‘stamping’ to find out when they were made (this could be on the outside or the inside of the tyre and generally after a DOT or between two DOTS).
- As a rule of thumb, they are good for only 5-6 years before the rubber becomes hard and loses its grip, which is all the more important when you are trying to brake in the wet. Remember that they could have been manufactured a year or more before they were fitted to your van.
- Tyre pressures are another set of numbers you should be aware of. If you can’t find any other information, set them at the car manufacturer’s fully-loaded highway pressures for the rear wheels if you are travelling on bitumen, remembering that high temperatures and fast cruising will cause their pressures to rise about 6-8psi. Over-inflation in very hot weather can just as easily lead to problems as can under-inflation. Also, ensure that the pressures match on each side of the caravan, as an imbalance here will cause the van to pull one way or the other under heavy braking.
LOAD THE VAN CORRECTLY
- Load your caravan where heavy items should be stored as low and as close as possible to the axle line and never in the tail. Overhead cupboards are for lightweight items such as clothes and packaged food. If you keep the weight evenly spread across the axle line, your ball loading and hence your caravan’s towing and braking stability should not be disturbed.
DRIVE TO THE CONDITIONS
- Leave a substantial gap between yourself and the vehicle in front.
- On twisting or downhill sections, brake early in a straight line and if you feel the wheels of your caravan lock up, get off and on the brakes, rapidly to regain traction.
Original source: Without A Hitch
For more towing information download the online National Towing Guide