Automatic Transmission Oil Cooler Upper and Lower Pipes

If replacement of automatic transmission oil cooler pipes is required, use only double-wrapped and brazed steel tubing meeting GM specification 123 M or equivalent. Tubing should be double flared.

NOTICE: Allow sufficient clearance to transmission oil cooler pipes to prevent damage or wear which may cause fluid loss.

REMOVE OR DISCONNECT
1. Raise and suitably support vehicle.
2. Fitting on radiator end of oil cooler lower pipe (857).
3. Transmission oil cooler upper hose clamp (862) from upper hose (860) and pipe (856).
4. Propeller shaft.
5. Rear axle torque arm.
6. Catalytic converter hanger.
7. Support automatic transmission with a transmission Jack.
8. Transmission support.
9. Lower the transmission jack slightly, to allow access to oil cooler fittings at transmission.
10. Fittings on transmission ends of upper and lower pipes (856 and 857).
11. Upper and lower pipe (856 and 857) from oil cooler pipe bracket (3).

INSTALL OR CONNECT

NOTICE: Always use the correct fastener in the correct location. When you replace a fastener, use ONLY the exact part number for that application. The manufacturer will call out those fasteners that require a replacement after removal. The manufacturer will also call out the fasteners that require thread lockers or thread sealant. UNLESS OTHER WISE SPECIFIED, do not use supplemental coatings (paints, greases, or other corrosion inhibitors) on the threaded fasteners or fastener joint interfaces. Generally, such coatings adversely affect the fastener torque and the joint clamping force, and may damage the fastener. When you install fasteners, use the correct tightening sequence and specifications. Following these instructions can help you avoid damage to parts and systems.

1. Upper and lower pipe (856 and 857) to oil cooler pipe bracket (3).
2. Fittings on transmission ends of upper and lower pipes (856 and 857).

Tighten
- Oil cooler upper and lower pipe fittings (856 and 857) to 27 Nm (20 ft. lbs.).

3. Raise the transmission.
4. Transmission support.
5. Remove transmission jack.
6. Catalytic converter hanger.
7. Rear axle torque arm.
8. Propeller shaft.
9. Transmission oil cooler upper hose clamp (862) to upper hose (860) and pipe (856).
10. Fitting on radiator end of oil cooler lower pipe (857).

Tighten
- Oil cooler lower pipe fitting to radiator (857) to 27 Nm (20 ft. lbs.).

11. Lower vehicle.