Mul-T-Lock key does not stick repair of defects

"The key is hard to stick"

It is an old apartment built 30 years ago.In such an old mansion, the Mul-T-Lock cylinders seem out of proportion.It seems that the landlord replaced the whole house a few years ago.

It was said that the key did not stick this time, but I washed the dirt due to aged deterioration.A lot of dirt came out, but a sense of incongruity remains.

The catch when inserting the key is not improved at all.When I looked at the key, I could see "burrs" on the tip.Have you ever dropped it?Anyway, it was improved when I fixed it with a hand file and confirmed it.