Difference between "pull" and "pull on"

My car manual says:

To prevent damage, NEVER hit or pull on the head restraints.

I understand pull on here as pull towards yourself, because it is the only way I can imagine the head restraints can be damaged.

I wonder if there is any difference between pull on and just pull. What is the additional semantics of on here or is it just redundant?

Solution 1:

You can, for example, pull a sled by pulling on a rope attached to the sled.

If you pull on an object, you are making contact with that object and applying force to it.

Pulling an object can be less direct.

Here are some examples of "pull on" where it is used to indicate where force is applied:

Crocheting Clothes Kids Love, Shelby Allaho et all, p42:

Pull on tail end of yarn to close ring.

Perspectives on Animal Behavior, Judith Goodenough et all, p93:

"When [Ravens] pull on food, such as the entrails of a dead animal, they eat the food while pulling.

Storey's Guide to Training Horses, Heather Smith Thomas p199:

If a young horse starts to bolt,the worst thing to do is pull on the reins

Even so, it's probably not a good idea to tie a cord to the restraints and pull on the cord.