About sailboat maintenance. You can have two identical items of equipment and perform exactly the same maintenance tasks, and failures will not be the same. Two identical items may need different maintenance. They may have differing criticality and also different outcomes when they fail. You must not assume Pump A which is the same as Pump B will fail the same. Why will swage on port side standing rigging fail when that on starboard does not. Why does one primary winch fail and the other identical one not?
You cannot maintain your way to reliability. No matter how much maintenance you perform, and no matter how intrusive and rigorous you are, you are always going to be limited by the inherent design and performance characteristics of the equipment. If its poorly designed the maintenance will not help much in reliability improvement. And fact is boats are full of things like this. The only answer to this is when a piece of equipment fails and you know it’s a design issue then best to eliminate it. That means choosing a replacement without the design deficiencies, or even rework the overall system design at the same time. Most older boats who have been fortunate enough to have hands on owners, will have gradually have eliminated these design issues, usually as a result of frustration. You can learn to live with a deficiency, a popular attitude or you can eliminate it.
Don’t waste your resources. Everyone is on a budget, and you have to reserve valuable resources by not wasting it on needless tasks. If the maintenance on your boat does not add value and is such that it actually reduces overall reliability then why bother? If you don’t really need to open up something and disturb everything then don’t as all you are doing is reducing reliability. Another important thing to remember is that much equipment is over rated for the job you are using it for. You do not have to over maintain to keep that level of performance, what you are seeking is reliable performance and functionality. To use borrow that old maxim or adage, “if it ain’t broke don’t fix it!”
If you have identified various failure modes around your boat, then use single maintenance tasks as far as practicable. Again over maintaining can come back and bite you. Where you have failure modes of high consequence such as loss of power, loss of propulsion and so on, then tasks maybe multiple if it will reduce failure.
Something the aircraft industry taught us is that intrusive and unnecessary maintenance generally leads to increases in failures as it introduces human error into the equation. This might be mistakes in reassembly, or use of defective parts, or lack of knowledge about lubrication, incorrect torquing or any other factor that might be mistakenly incorrect. Whatever you decide to do on board, before you do it have a clear and legitimate rationale before you undertake the maintenance. So always review your maintenance regime on your boat, keep good records of your work and adapt to changing circumstance. Make your life easier by eliminating tasks that don’t improve things. Consider where relevant changing your time based overhaul tasks into condition monitored ones. It is not easy but try and use condition monitoring to ascertain how much life is left before failure. If a bearing is hot, and lubrication only offer temporary respite then time to change the bearing before you suffer a catastrophic failure. Again we come down to consequences, if the bearing fails to severely damage the pump, or motor or whatever, meaning its no longer a bearing failure but a possible total system and even boat failure. Hesitation and procrastination is often ruinous, so when a condition is detected then it’s a value judgement on the consequences of not intervening. All about sailboat maintenance and boat maintenance.