I have a '50 L with a low volume oil system. It recently stopped pumping oil. The crankcase is more than full of SAE40. Before I start pulling oil lines to check for blockages and pump operation I noticed a fair amount of play on the timing pinion shaft where it exits the oil pump cap. It is leaking some oil there and would likely allow air to enter. Would this account for the loss of oil pressure or do I have two separate problems, a worn bearing with a bad seal and a separate lube system problem? How involved is replacing the timing pinion bearing and bearing cap double seal? If they are unrelated the lube system problem is the more urgent issue and suggestions for diagnosis are welcome.