In most ships, the cable attached to the release handle goes around a
"walking pulley" and then goes to the nose tow hook. The walking
pulley is attached to the CG tow hook. When pulling, the weaker tow
hook will open first, then the tow hook with stronger springs will
actuate.

At Hobbs, last week we found an LS-8 with the same problem. It had a
rats nest right on top of the walking pulley. Every time the pilot
pulled the release, some of the rats nest was pulled into the pulley.
You might pull the seat pan and have a look at the cable runs.
Lubricate both tow hooks and the walking pulley while in there.
JJ