Buying a Horsebox Checklist
Using a bright torch, look underneath the horsebox and look for any visible signs for rust, rot or holes. Also check the horse area for rust, especially around the joins where any panels meet. Rusty areas can be repaired but can be costly. Bear this in mind when negotiating with the seller.
Check the top and bottom of the engine for any leaks. Some oil leaks may be superficial but crankshaft seals and be costly to repair
Run the engine for at least 10 minutes on idle. This will show whether the engine is overheating or indicate any issues with the cooling system and head gasket.
Test the ramp. Get someone to stand on the ramp to see how easy the ramp operates. Check that the springs and hinges are intact. The ramp may labour a little when under very heavy loads, it shouldn't stutter or jump.
Check for any warning lights or error messages on the dashboard, make sure the engine is running. Some warning lights may just be service counters but make sure you ask the seller
Ensure you have all of the keys and that all of the locks and keys are working correctly
Check the basic operations of all lights, wipers, horn, windows etc
Check all tyres are legal and have sufficient tread, check they have not perished and also inspect any spare wheels
Horseboxes with a living area have a separate battery from the engine, make sure items are working in the living area, i.e fridges, lights etc
Take it for a test drive. Make sure it feels safe, use your judgement. Check that the clutch doesn't bite right at the top of the pedal travel. Ensure the brakes work evenly and that the steering doesn't have any play.
Check to see if there is any warranty with the horsebox and make sure you have this in writing. Private sellers will probably not offer this, but dealerships or companies will often have a warranty policy.
Get an HPI check on the vehicle. You can do this here https://hpicheck.com/. It costs roughly £10 but can prove to be priceless if you do find there is an outstanding debt or that it's been written off
Look at the V5C Logbook and make sure the Registration number, chassis number, engine size, colour and chassis type all match.
Make sure the lorry you are buying is sufficient for the load you are carrying. A horse lorry described as 7.5T or 3.5T means the maximum weight the lorry can carry. The lorry’s payload is the difference between the unladen weight and the maximum weight. This can be measured on a public weighbridge, a certificated will be provided, and will then allow you to work out how many horses people etc you can take on the horsebox without exceeding the legal limit.