BD Diesel Performance Rear Frost Plug Plate cures coolant leaks by covering a leaking, missing, or corroded OEM freeze plug. Coolant pressures can reach up to 70 psi, which can cause corroded freeze plugs to fail. May be used with TCC crossover tube, but it is not required. The frost plug plate can be easily installed while the transmission is lowered, but may also be added while the transmission is in place.