GMC 1976 ZEO 6083 Maintenance Manual page 658

units prior to assembly on a vehicle or to check
detached units that may have been removed for the
purpose of making vehicle repairs after a collision.
A suitable arbor press should be used to com-
press the unit 3/8" . Observe ifit returns to its normal
position. If not, this unit should be replaced .
are:
Recommendations for handling energy absorbers
1 . Do not attempt to repair .
2. Do not weld.
3 . Do not apply heat.
INSPECTION
WARNING : BE SAFEI PROTECT YOUR EYES .
WEAR APPROVED SAFETY GLASSES.
4. Relieve gas pressure prior to disposal of a unit .
Make an indentation with a center punch in the
small cylinder section of the energy absorber (recom
mend "WARNING" label on the unit as a target
area). Then, use a 1/8-inch drill to penetrate the
small cylinder and relieve gas pressure (See figure 4).
INSPECTION AFTER COLLISION
If the collision was so severe that the bumper did
not return to its original position, the energy absor-
ber(s) will require replacing.
WARNING : BE SAFEI PROTECT YOUR EYES.
WEAR APPROVED SAFETY GLASSES .
1 . Stand clear of the bumper.
Figure 4-Relieving Pressure from Energy Absorber
FRONT
REPLACEMENT
BUMPERS
14- 3
2 . Provide positive restraint, such as a chain or
cable .
3. Relieve the pressure by drilling a 1/8-inch hole
in the piston tube near the bumper bracket (See fig-
ure 4).
4. Remove the unit from the vehicle as described
under "Replacement" only after the gas pressure has
been relieved .
IMPORTANT:
Prior to replacement, be familiar
with procedures given under "INSPECTION"
of energy absorbers.
1 . Remove bumper by removing both bumper
bracket thru bolts (See figure 5).
2. Remove the four bolts and nuts securing en-
ergy absorber to frame.
3. Secure new energy absorber to frame with
bolts and nuts . Nut torque is 25-30 foot-pounds.
4. Install bumper on energy absorbers and secure
with thru-bolts.
Nut
torque is 40-50 foot-pounds.
NOTE:
Be sure lower bracket is properly in-
stalled (See figure 5) before tightening retaining
nut.
12-16 FTABS .
LOWER BRACKET
A-3685
Figure 5-Front Bumper Bracket Mounting