A/T - Cooler Lines Cracked/Leaking

9230chevy01

GMC NUMBER: 92-7A-84

GROUP: 7A Automatic Transmission

DATE: April 1992

CORPORATE
NUMBER: 267102


SUBJECT:
AUTOMATIC TRANSMISSION COOLER LINES CRACKED/LEAKING

MODELS:
1988-92 C/K TRUCKS EQUIPPED WITH 6.2L DIESEL ENGINE AND 4L60 (MD8) OR THM400 (M40) AUTOMATIC TRANSMISSION


Some owners of 1988-92 C/K trucks equipped with a 6.2L diesel engine and a 4L60 or THM400 (RPO MD8 or M40) automatic transmission may experience cracked or leaking automatic transmission cooler lines at or near the transmission fittings.

These cracks may be caused by the cooler lines going into resonance or vibrating at low engine idle speeds causing the lines to fatigue. To correct this condition, replace the cracked/leaking lines and install a support bracket.

SERVICE PROCEDURE

1. Replace the cracked/leaking line(s) using tubing (P/N 1324714).

^ Double flare both ends of the line and form the line to match the shape of the line which was removed.





2. Install a bracket assembly (P/N 15684042 (C-Truck) (Figure 1) or P/N 15684043 (K-Truck) (Figure 2)) to the transmission inspection cover bolt.

3. Install a clamp (P/N 15518639) around the transmission cooler lines and attach it to the bracket assembly with a bolt (P/N 11508023) (Figures 1 and 2).





SERVICE PARTS INFORMATION





WARRANTY INFORMATION
For vehicles repaired under warranty use the chart illustrated.