Some Owners of 1988 - 1990 C/K Trucks may be expressing concern that their seat will not tilt forward without using the latch release mechanism. 1988-90 extended cab models equipped with A50/A57 and 1990 regular cabs with A52 will not exhibit this condition. This condition has been determined to be a result of a bind in the seat back inertia locking mechanism. This bind is a result of a foam buildup causing the pendulum mechanism to lock. Use of the latch release mechanism will overcome any interference caused by the foam. Hence the seat back can still be tilted forward.
The following Steps should be followed to correct the inertia lock.
1. Remove seat back to expose the hinge assembly, shown in Figure 1.
2. If equipped remove the inertia lock cover assembly (added in 1989).
3. Locate inertia lock pendulum as shown in Figure 2. You will notice foam trapped below, behind and on top of the pendulum.
4. Clear away any trapped foam and confirm that the inertia mechanism swings freely.
5. As shown in Figure 3, pull back cloth or vinyl covering and cut away about 3/4 of an inch of foam from near the hinge assembly.
6. Reinstall inertia lock cover (if equipped) to hinge assembly.
7. Clear away any excess foam that may be laying loose to.ensure that no foam remains to get caught in the pendulum again.
8. Place cloth cover back over the foam.
9. Reattach seat back.
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.