How to Replace Lower Transmission Line 2002-2009 Chevrolet Trailblazer 4.2L
Difficulty: Advanced · About 120 min · Chevrolet Trailblazer
Replace the lower transmission cooler line on the 4.2L Chevrolet Trailblazer shown. Identify the correct cooler line before disconnecting it, collect fluid, and check the transmission level using the vehicle’s service procedure after the repair.
Tools you will need
- locking pliers
- line wrench
- drain pan
Parts and supplies
- Lower transmission cooler line
Steps
Identify and disconnect the line
With the vehicle secured and cool, locate the two transmission cooler lines along the passenger side. Confirm which is the lower line being replaced. Remove its plastic locking cover and the small retaining clip, then separate the line from the connector.
Remove the old line
If the old line is seized in its connector, carefully cut only the discarded line and use locking pliers to twist and pull its end free. Support the line as you work underneath and release its remaining fittings and retainers along the route.
Route and connect the replacement
Compare the new line with the original and follow the same path, keeping it clear of hot or moving components. Seat the connections fully, reinstall the retaining clip and plastic cover, and secure all original supports.
Check for leaks and fluid level
Start the vehicle and inspect every disturbed connection for leaks. Check the transmission fluid level using the specified procedure for this vehicle and correct it with the approved fluid if needed.
Check your vehicle’s repair manual for exact specifications and fit.