The parameters are right and the part is good, but once fitted it still feels wrong. Problems like this almost always come from installation. These four are the usual suspects.
1. Mounting position (the engagement point)
This is the number one cause.
The buffer has to engage at a point where the slide has already carried the drawer up to speed. Too early and the drawer is hard to push; too late and there is no room left to decelerate.
The check is direct: push the drawer slowly and notice where the resistance starts to rise. That is the engagement point. It should sit in the last part of the travel — not in the final few millimetres.
2. Alignment
The working direction of the buffer must match the direction the drawer travels.
If it is mounted a couple of degrees off, the slider takes a side load. At best that means a gritty feel and noise; at worst it wears unevenly and the seal eventually fails. This is a classic "it broke after a few months" cause.
How to check: fit it, then open and close the drawer several times and watch whether the slider tracks to one side.
3. Clearance
Confirm there is no interference anywhere along the travel:
- The buffer must not rub against the cabinet or neighbouring parts.
- With the drawer fully closed, the buffer must not be forced against its end stop — bottoming it out keeps it under load permanently and shortens its life.
- Cables, slide ends and the back of the front panel must stay out of the slider's path.
4. The slide's own end stop
Many slides have a self-closing or end-stop feature of their own. If the slide's end stop arrives before the buffer has finished its travel, the buffer never completes — and the symptom is a soft-close that only does half the job.
That is not a fault in the buffer, but it can only be solved by moving the mounting position or by using a model with the right stroke.
Do this as soon as it is fitted
Open and close it by hand ten times, listening for sound each time and feeling whether the resistance curve is consistent.
If the first few are fine and it gets worse, you are looking at uneven wear or interference. Ten consistent cycles is what "correctly fitted" looks like.
The check takes under a minute and prevents most on-site complaints.