G 2500 3/4 Ton Van V8-379 6.2L DSL (1986)
Grille: All Technical Service Bulletins
Grille - Mounting Tab Breakage
GMC NUMBER: 91-10-156
GROUP: 10 Body
DATE:
October, 1991
CORPORATE NUMBER: 161509
SUBJECT:
LH GRILLE MOUNTING TABS BREAK (APPLY SEALER TO BOLT)
MODELS:
1991 AND PRIOR G-VANS
Figure 1
Some 1991 and prior model year G1, G2, and G3 vans may experience cracking of the upper left grille mounting tab. Investigation has shown that the
primary cause can be attributed to brake fluid contamination at the mounting tab.
The master cylinder provides a drip path to the radiator tie bar, which is in close proximity to the upper left grille tab mount. A recess in the radiator tie
bar allows any spilled brake fluid to accumulate and drip through the fastener hole onto the grille tab.
This causes the grille material to deteriorate and may result in a broken mounting tab at this location.
To correct this condition it is necessary to remove the upper left tab mounting screw and apply a small quantity of silicone sealer (P/N 1052917) or
equivalent under the washer. A new screw, with the sealer already installed, has been released for 1992 production. This will prevent brake fluid from
dripping down onto the grille mounting attachment (figure 1). The sealer should also be applied when any G-van comes in for brake service.
If the mounting tab is found to be broken, the complete grille assembly will have to be replaced, and sealer must be added to the upper left tab mounting
screw.
The service technician should always be careful to fill the master cylinder according to specifications and avoid spillage. In the event of brake fluid
spillage, thoroughly clean the tie bar. See section 5A of the G-van service manual for on-vehicle brake service.
Notice:
Brake fluid can damage electrical connections and painted surfaces. Use shop cloths, suitable containers, and fender covers to prevent brake
fluid from contacting these areas. Always reseal and wipe off brake fluid containers to prevent spills.
