C 1500 Truck 2WD V8-350 5.7L (1989)
Technical Service Bulletin # 89T776A
Date: 890701
Engine - Oil Cooler Line Leaks (Replace Hose)
GMC NUMBER:
89-T-77
GROUP:
6A - Engine Mechanical
DATE:
July, 1989
CORPORATE
NUMBER:
966102R
SUBJECT:
ENGINE OIL COOLER LINE LEAKS (REPLACE HOSE)
MODELS:
1988-89 C/K WITH 4.3L, 5.0L, 5.7L, AND 7.4L ENGINES (VIN CODES H, K, N, Z)
Some 1988 and 1989 C/K Trucks with 4.3L, 5.0L, 5.7L, and 7.4L engines and engine off coolers (KC4) may experience a leaking oil cooler line. This
leak condition may be caused by the line contacting the power steering gear box (located in the left front of the vehicle alongside the frame rail) and
chafing a hole in the line. If this condition is encountered, it can be repaired by installing the new design lines, which provides additional clearance to the
gear box. On all affected vehicles, it will also be necessary to add a primary or secondary hose protector or both to the cooler lines. These protectors
provide additional protection from the steering gear box for the cooler line.
