Alon,
fridges tend to be reliable. Elements sometimes go after many years of use but do not worry is they can be fixed and you will not be without cooling power as if the 140 is down you will still have the gas.
- Run on 240v for a day before leaving to get fridge nice and cool.
- switch over to 12v on the fridge for your journey, you should see the green switch light up when engine is running but might cycle on/off.
- if journey is a long one put a bottle of frozen water in the fridge to help it as 12v is not the most efficient power source.
- try it on gas at some time as this can be tempremental and you may have a site with no hook-up, gas normally gives the coldest running temperatures.
- when temperatures rise into the high 20s the fridge may start to struggle, try and keep this side of van directly out of the sun, pop the outside vents off and run on gas if your beer is not cold enough.

Colin

You could always fit extractor fans to remove the heat build-up from the rear of the fridge thereby improving its efficiency in hot weather.

See link: Fridge fans