Troubleshooting Master Lock Trailer Coupler Lock Key Stuck

Published 10/21/2022

Products Featured in This Question

Master Lock Trailer Coupler Lock - 1-7/8", 2" and 2-5/16" Ball Couplers

(915)

$35.75

LubriMatic White Lithium Grease - 14 oz. Cartridge

(78)

$13.10

Question:

Trailer hitch Master lock won’t open? Key won’t turn all the way to release cylinders on my trailer hitch theft lock where the tow ball goes into

asked by: Sidney C

Expert Reply:

If you're having issues with the key turning all of the way to release your Master Lock coupler lock, like part # ML389DAT, then I recommend using some spray lubricant like the LubriMatic White Lithium Grease # L11354 to help loosen up any dirt that might be in the lock.

Spray it and let it sits for a minute or two and then with the key inserted lightly tap the key with a rubber mallet to make sure it's fully seated. If this doesn't work then you'll either need to drill out the lock or have a local locksmith come out and look at it to release the lock for you.

expert reply by: Jon G