The 1989 'C and H' models introduces a new 0-ring joint design for the A/C system which will increase durability of the joint seal by providing a second 0-ring seal.
The dual 0-ring fitting design consists of: (Refer to Figure 1)
o Aluminum alloy externally threaded fitting which is brazed or welded to an aluminum tube.
o Free spinning, plated steel, internally threaded nut.
o Precisioned machine male piloted aluminum tube end which accommodates two 0-rings.
When attempting to service the dual 0-ring joint, the following procedures should be followed:
o *Disassemble:
o Make sure A/C system is completely discharged.
o Use Kent-Moore Tool J 38042 (Dual 0-ring disassembly tool), to separate the joint while loosening female nut. Refer to Figures 2, 3 and 4.
o Remove and discard 0-rings.
- Use nonmetallic tool when removing 0-rings to prevent chance of damaging seal surface.
o Avoid excessive stretch and twisting of replacement 0-rings.
*Reassemble 0-ring joint
- Carefully align forms (tubes) for pilot to bore insertion and push together completely (Refer to Figure 6). - Slightly oiling the bore and 0-rings will aid insertion.
o Tighten steel nut. A torque of 20 - 27 Nm (15-20 ft. lbs.) is required on all dual 0-ring joints.
*NOTICE: The use of proper wrenches when loosening or making corrections is important. A backup wrench should be used on the brazed or welded fitting to prevent distortion of A/C lines.
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.