1994 Mitsubishi Pajero

Engine Cooling problem
1994 Mitsubishi Pajero 4 cyl Four Wheel Drive Automatic

hi, my 4x4 recently overheated but rather than stop i kept going but not very far, my engine cut out and i was towed home by recovery.

now upon inspection i found that my radiator had a large crack in it so i bought a new one. i drained everything out the old radiator and reserve tank flushed it and installed the new radiator, top it up with 50/50 coolant and water.

i left of the radiator cap to "burp" the air out but everytime i turn the engine over it turns but will not start and huge amounts of pressure and water comes out my radiator.

any ideas

thanks