If you keep to a maintainance schedule you will probably find there is very little wrong with your trailer unless the trailer is abused but if it is neglected 1 problem can lead to another and end up costing a lot of money or cause an accident.
If the trailer is left to stand it is still recomended to service the trailer as brake parts, bearings and couplings can all corrode or Seize through lack of use, tyres can perish and electricals can corrode and stop working.
A couple of problems we regularly find on trailers that don’t come for service regularly are.
Brake cables seize and due to the lack of movement the expander seizes this then usually leaves the brakes to rest in an open position- rubbing the brake drum that wears the Shoes and in bad circumstances they damage the drums. This also effects the brake effiency and the amount of fuel used to tow, When you really need the brakes they are not there this can cause an accident for the cost of a brake cable.
Wheel bearings failing. With wheel bearings you usually will get a bit of warning (play) before a bearing fails. When a wheel bearing fails the whole wheel can come off – this can damage the shaft as it comes off or if the shaft hits the floor this means a new axle / suspension unit at an high cost also a trailer wheel can cause a lot of damage/ injury if it hits something or a person.