coolent is leaking from hole at bottem of pump
The first thing to do is to check the water pump for evidence of shaft
bearing wear. This can be done (with the engine OFF!) by grasping the fan
and attempting to rock it (wobble it) fore-and-aft. If any play in the pump
is noted replace the water pump immediately. If no play is found, continue
If you haven't already done so, have the cooling system pressure cap checked for proper relief pressure. If it is operating within its specified pressure range, replace the water pump. If the cap is not operating within its specified pressure range, replace the cap and monitor the pump for continued leakage. If leakage continues, replace the water pump.
Coolant leaking from the pump housing weep hole is an indication that coolant is getting past the water pump shaft seal. This can simply be a result of a worn seal, and it can also be caused by radial looseness in the water pump shaft bearing(s). Either of these conditions would call for pump replacement. However, the pump shaft seal will also often be lifted of its seat by excessive cooling system pressure. This in turn can be caused by a pressure cap that is not relieving at its design pressure, or by the wrong pressure cap being fitted. In this case, the leak will often stop when a proper pressure cap is installed.