Thermostat? Very possible that while changing the pump, some schmutz (or small pieces of gasket) got into the system and now lodged in the thermostat, preventing it from opening (or closing) all the way. Same is possible, or other build up, in radiator or water jacket. I'd start with thermostat (cheap/easy) and then do a flush if that doesn't work.
Frozen/seized clutch pack, time for a rebuild.
It shouldn't have frozen if you have coolant in it
On a 1971 Kawasaki 500, how do you unstick a frozen clutch? The clutch plates must have fused together in the 7 yrs it sat still.
no because you need the clutch to start and stop the car
Typical causes for this car to overheat would be blown head gasket, coolant leak, thermostat frozen in closed position, failed fan clutch, failed auxillary fan or auxillary fan switch, blockage in radiator or coolant lines or an oil leak.
Sounds like you may have a frozen clutch pack. No quick fix there, talk to a transmission shop.
first if coolant and water mix was not prepared as needed to your state climate .coolant on your rad will continue to freeze ,...if it is frozen run hot water on rad assly also installing a block heater will help in heating you engine before starting on mourning's.knowing the state you are from ask local mechanic's what is the mix rate or percentage in which to mix coolant and water,...
The coolant could have frozen in the radiator. If that happens the coolant in the engine will just get hotter. It could also be the thermostat.
Possible causes: Insufficient/no coolant in the system; insufficient antifreeze in the coolant and the coolant is frozen: the water pump is faulty and is not circulating the coolant; the belt that drives the water pump is loose or missing.
Maybe the clutch is frozen. Has it sat up for a while?? If so, the clutch assembley could be full of rust and has frozen the clutch fingers to the pressure plate. You may have also dropped a gear or synchronize and it's stuck in some of the teeth on the third gear ring.
The cooling system fan clutch is frozen and locked up. Replacement of fan clutch is necessary to correct the problem.
Ask This Old House - 2002 Installing Garage Door Preventing Frozen Pipes 7-24 was released on: USA: March 2009