I am changing the water pump on my 1300 Marina engine. The first bolt snapped at the head and the second began to destroy its head. The other 2 are also tIght so I stopped in case they snapped off flush with the block. I suspect this is the original 45 year old pump. There is hardly any way for penetrating oil to get to the threads through the gasket between the pump and the block so what to do next? The question is, are the bolts seized to the aluminium casting or to the block?
I think I may be able to get a small grinding wheel in a flexible drive on to the bolt heads and then persuade the pump to come off. Or, more drastically, I could destroy the pump first with angle grinder/cold chisel/drill etc. I don’t want to end up having to dismantle the front of the car in order to drift broken studs out. Any advice gratefully received.