The BCD may seem to be a relatively simple thing that we constantly rely on but in reality it is a incredibly complex piece of equipment when you take into the number of mechanisms and features that are crammed into them these days. It is also the piece of kit that is probably most neglected when it comes to maintenance. Honestly, how many of us have their BCD serviced every year or even as often as their regulators? I have been a equipment technician for a good few years now and it still amazes me at the state that some customers let their BCDs get into before bringing it in for a serious overhaul. Your BCD has just as much chance of causing a serious situation or having to abort a dive as your regulators if its not looked after properly. A poor inspection and maintenance plan could lead to the inflator sticking, a dump valve failing and a failure from unnoticed damage to name a few. Preventative maintenance is your friend here and will help to keep your BCD in full working order.
Obviously the most important mechanism fitted to your BCD, it directly controls the buoyancy characteristics of the whole BCD. A tiny leak coming out or a valve that has failed closed is manageable but a valve stuck open is instantly a serious issue. An experienced diver will automatically come to the solution of dumping air continuously until the quick release connection has been removed, the diver can then use the oral inflation to safely exit the water. How quickly do you think you can carry out that skill? After EVERY dive, not just salt water dives, the inflator should be thoroughly rinsed both externally to remove sand, grit or salt crystals from around the buttons but also flush the exhaust side through with fresh water to remove any foreign objects from the exhaust seat, helping to prevent those little leaks. Washing it fresh water and allowing it thoroughly dry before storage will also help to prevent corrosion from forming.
Another crucial part of the BCD are the dump valves. Whilst most dump valves are designed to be over pressurisation valves this only prevents the BCD from rupturing due to over expansion, not preventing you from rocketing to the surface because you can’t release the excess air and reduce your buoyancy. Similar its not a good situation to be in if you are unable to increase your buoyancy because your valves are stuck open. Take care of your dump valves and they’ll look after you! As always the valves need to be rinsed with fresh water after diving but look for objects stuck in the valves that could cause the mechanism to fail such as sand and grit that could jam or prevent sealing. Check that the valve is secured. Also check pull dump cords for deterioration, its a bit inconvenient if the cord snaps off when you go to use it. Don’t forget to check the shoulder pull dump that is incorporated into the inflator and hose assembly, check it for excessive play before the dump activates. Unexpected play could mean that the wire cord inside the corrugated hose has stretched. At the end of the day if the valve is stuck to the point that it endangers you and/or your buddy on a dive it needs to be professionally repaired.
Lets not forget the actual bladder, that needs to be looked after as well. Go over the whole of the external surface checking for material deterioration, stitching fraying, bent or broken clips, etc. The inside should be periodically washed out with an anti-bacterial agent to eliminate any nasty things multiplying in there. BCD safe cleaning products are available to make this easier, if in doubt check the maintenance and cleaning section of your BCD manual.
As with everything else, rinsing the pockets and locking mechanisms will help to maintain good working order. Grit and sand can make locking and release of pockets stiff and frayed or damaged stitching could lead to weights being lost.
Another culprit for leaking or stuck inflators is the quick disconnect and schrader valve. A quick squirt of silicone lubricant worked into the valve whilst the air supply is off should help to free up a troublesome quick disconnect. Remember to wash the quick release after every day of diving to prevent salt build up and corrosion. Whilst preventative maintenance and great after dive care will help to keep your BCD in reliable condition for longer, nothing is better than a full service carried out by a qualified technician periodically will make sure that every component your BCD is safe to use.