As long as you have a full expansion tank[recovery tank],and the hose and cap from it are OK, I'd replace the radiator cap as a cheap test. Sounds like it's stuck or leaking pressure.


'92 SR Montero, Green, with 31" Yokohama Geolandar A/T Plus Tires, Mitsu factory fog light kit, on-board air compressor,Sony Radio and 10 disc changer. 213K and counting.....
Stock & Happy otherwise