Just had a routine look over the md22 in Alchemy ,and found the raw water pump belt guard sitting on top of the engine block. The guard had sheared off at the single mounting bolt. It looked like metal fatigue but i,m no expert. Quite lucky that it did not fall into the path of the belt. A new belt would be one thing but a mangled pulley or pump very bad. Geoff [in Concarneau]
A common fault. I've seen it on most MD22 (B only, A has the pump directly on the camshaft).
I've epoxied ours back on with a reinforcement of metal epoxy and eventually spraypainted the repair.
I think they probably get too much rotational force on the cover when the big bolt on the other end is torqued down to fix the pump and tension the belt. Our repaired one has held for a few years now, but it's much thicker than before. Does always seem to pop up onto the engine rather than down into the belt, luckily.
Mine never had a belt guard (since I own her). Never missed it.