I have recently replaced the thermostat, radiator (and cap,) and water pump due to different issues. Now the coolant, when full and accelerating, pushes into the reservoir and leaks out the top. What could be causing this issue? thanks!

 

bad head gasket.

if it overheated when you had "different issues" then you probably compromised the gasket. when you accelerate, you create higher cylinder pressures which will cause cooling system pressure to exceed cap pressure which pushes coolant into the reservoir

 

you can have your coolant tested for ehxaust gases to confirn, but hate to say it sure sounds like a blown head gasket

 

lucky gasket

 

Thanks for the input, I will check it and let you know the progress