Having been in the car repair business for 39 years, it still surprises me how many customers defer important maintenance repairs that will cost them many times more down the road. For example, water hoses dry out and fatigue over time and have a usable life of around 8 years or 80,000 miles. Changing a set of hoses on a new German car is expensive, usually around $1,000. Most of my customers change the hoses one at a time as they break. This a very costly and potentially dangerous approach.
Your average new German car has around 9 cooling hoses. By changing the hoses one at a time, you pay more for labor. Every time the car is brought into a shop part of the labor costs come from inspection, disassembly, and a test drive. It’s a cost built into every service that will be charged each time you come in to repair another of the hoses. In addition, you pay for labor to drain and refill the cooling system and for the antifreeze every time it is drained and refilled. In the end, changing the hoses one at a time costs between 150%-200% of doing them all at once. You also run the risk of overheating and ruining the engine every time a hose breaks. If the engine is damaged, you could be paying anywhere between $10,000 and $30,000.
As you can see it is penny-wise pound-foolish not do all the hoses all at once. It is important with any recommended repair to ask the shop what the ramifications are for not doing recommended repairs. In some cases, it is ok to defer maintenance, but in most, immediate repair is the safe bet.