National Trailer & Towing Association
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Boat Trailers: Additional Operating Advice

It is recommended that hubs and brakes are not immersed in water, particularly salt water, but if they are, then the following advice can be offered:

  • DO NOT immerse when the hub is hot i.e. Straight after a long journey, but wait until the assembly has cooled, otherwise a vacuum will be created, making the ingress of water even worse.
  • Keep immersion times to the very minimum and DO NOT leave the trailer standing in the water after the boat has been launched.
  • After immersion in salt water, the hub assembly and indeed the whole trailer should be thoroughly hosed down with fresh water.
  • Do not park the trailer for prolonged periods with the handbrake fully on, particularly when the hub is wet. If necessary, chock the wheels.
  • It is recommended that the trailer is serviced more regularly than otherwise would be the case and certainly at least every 3 months irrespective of mileage. This must include a brake strip down and re greasing of bearings.
  • Hubs with unitised bearings cannot be greased and whilst they are more resistant to the ingress of water, particularly if allowed to cool before immersion, they are NOT waterproof. Repeated immersion in water will eventually lead to their failure.
  • Bowden cables generally are not provided with a lubrication medium i.e. A grease nipple, as the introduction of grease will inhibit the movement of the inner cable within the specially designed and coated outer casing. There is also a very real danger of excess grease contaminating the brake linings thus rendering them ineffective. Practical experience shows that a periodic soaking in thin oil e.g. WD 40, particularly over the winter months goes a long way towards avoiding seizure problems.

Following the above advice and recommendations will do much to reduce the devastating effects of water, particularly salt water, but cannot guarantee that problems will not occur. 

N.B. It is important that reference is also made to the brake and hub manufacturers' maintenance instructions.

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