COVER 3983671 - Caterpillar

TECHNICAL INFORMATION BULLETIN August 21, 2002
PRODUCT FAMILY All Machines equipped with Computer Aided Earthmoving System (CAES) or Computer Aided Earthmoving System Basic (CAESbasic)
Component Code(s) 7604SUBJECT:
Cracks have been found in the radome of the 167-8930 GPS Antenna and the 194-8015 GPS Antenna.
PROBLEM:
Cracks have occurred in the screw relief area of radome parts that are mounted to the top of the 167-8930 GPS antenna ground plane and the 194-8015 GPS antenna ground plane. The 167-8930 GPS antennas and 194-8015 GPS antennas are used with CAES and CAESbasic systems.
All the failures seen have occurred in the screw relief area. The cracks can be large and easy to see, or small and difficult to find. Any cracking of this part will likely allow water to leak into the area of the antenna. Please avoid pressure washing this area.
The serial numbers of the affected antennas are 0220265600 and up.
For antennas that fall within the effected serial number range, closely inspect the antennas for any sign of cracking. Cracking can occur in the screw relief area on the radomes.
Illustration 1. Cracked Radome Housing
1. Crack in the radome housing.
Notice: Avoid pressure washing the antennas. All unnecessary contact with water should be avoided until a permanent resolution to this issue has been identified. Antennas with cracks will likely experience failure due to water incursion.
SOLUTION:
A temporary preventative measure can be applied to antennas with the potential for this failure by filling the screw relief area with RTV to protect against any cracks, which may occur. The procedure is as follows:
Clean screw relief area with Isopropyl Alcohol using a cotton swab.
Apply 8T-0065 Sealant to the screw head. Completely fill screw relief cavity. Ensure screw head is completely covered. Smooth to finish.
3. Apply 8T-0065 Sealant to all 12 radome screws. Allow 8T-0065 Sealant to cure for 4 hours.
Illustration 2. Radome screw with sealant applied.
2. 8T-0065 Sealant
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