Some 1990-91 "N" cars equipped with a 2.5L (VIN U) engine may experience a rub through at a point where the "Y" Type lower radiator hose routes by the right front engine mount. If conditions are right, the hose can contact one of the bolt heads on the mount causing a rub through. This may result in a loss of engine coolant.
To correct this condition, replace hose assembly with a 1989 production style hose. This hose is formed differently and does not come in contact with the mount bolt. (Refer to the illustration below for differences)
The lower hose must be replaced any time a rub through leak is noted. It is also suggested that it be replaced if any contact is seen during routine service.
Part numbers for lower hose assemblies:
Current (1990-91) 22551441 (DO NOT USE) Replace by (1989) 22538799 (FOR USE IN 1989-91 APPLICATIONS)
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.