Door Closer Maintenance, Repair and Adjustment Info

EXCERPT: For adjustment and repair of Door Closers, often used in offices and commercial buildings. Also known as: Mechanical door closer, office door closer, automatic door closer.

For information on pneumatic storm door closers, see this article: Storm Door Closer Maintenance, Repair and Adjustment

Disclaimer: This information may be inaccurate, incomplete, or dangerous. You are responsible for your actions. I caution you to NOT disassemble the main cylinder, your closer may have a strong spring inside that can cause serious injury if an end cap is removed.

This article is an updated version of the original page.

Basic Operation

The operation of a door is controlled by the Door Closer in 3 basic zones:


Instructions here are for a properly functioning door closer. If your door closer is not functioning properly, see Troubleshooting section before adjusting.

Adjustment: Things to consider

Typical door closer

e.g. LCN, Norton/Sargent/Arrow may have the following adjustments:

Adjustments (typical)
S Sweep Rate adjustment for long closing swing of door
L Latch Rate adjustment for short latch swing of door
BC Backcheck Adjustment to slow/limit the door’s max open angle
PA Power Adjust Adjustment for spring tension (less common)

To adjust a typical closer: Adjust a little at a time – try a 1/4 turn to start, open the door between adjustments to check the difference.

Adjust in this order:

  1. Sweep speed (and Power Adjust if necessary/applicable)
  2. Latch speed
  3. Backcheck

Kawneer door closer

For Kawneer models with a single combination adjustment for Sweep and Latch. One screw adjusts both settings:

Kawneer Adjustments
Screw type/loc. The Sweep and Latch are both adjusted with a single screw
Beveled Edge (see chart below) Sweep Sweep is adjusted by turning screw CW to increase resistance/slow closing speed
Latch Latch is adjusted from least to max within 1 revolution
Opposite side Backcheck Adjustment to slow/limit the door’s max open angle

To adjust Kawneer closers: Set your Sweep speed first, then turn adjustment screw +/- one half turn in either direction to attain proper Latch speed.


Most problems are caused by low oil.

Low oil level can look like:

Oil loss is usually due to:


Smaller Door Closers are relatively inexpensive, figure in your time, and consider replacing them.

Heavy Duty Door Closers can be expensive and hard to find replacements for

Check to see that your door closer is not under warranty. The following instructions may void any warranty you have.

Repair seals / Refill Oil:

Consider Hydraulic Jack Oil in the automotive section of a major store. I have also successfully refilled door closers using 3-in-1 household oil

  1. Wear Safety Glasses
  2. Note the leaks, and their apparent origin
  3. Remove the door closer unit from the door or top jamb
  4. Move unit to a suitable workspace (oil will drain, and sometimes squirt from unit during refill process)
  5. Remove adjustment screws or other hardware to gain access to seals
  6. Remove seals, or take the screw/shaft with the o-ring on it to the hardware store
    • Match the o-ring with a new one at the hardware store
    • optionally, buy an assortment of o-rings from Harbor Freight
  7. Typical: re-insert BC adjustment screw, tilt and hold closer so that it's on its end, with the S and L adjustment screw ports facing upward
  8. Fill port(s) with oil, slowly moving the closer Arm to distribute oil internally. If you move too fast oil may squirt out!
  9. Fill to top and re-insert adjustment screws with fresh seals

Tip: If you want to save yourself some time adjusting, count the number of turns while you remove the adjustment screws. When you reassemble you can turn them in the same number of times to get close to your original settings.

Arm Shaft Seals: If you’re changing the Arm shaft seals, here’s a few tips. Be careful if removing the internal Spring. The Arm shaft seals on your closer might be accessible after removing the retaining ring on the pinion shaft (where the arm is attached to the closer) note the position of the arm on the pinion shaft, you will need to correctly align the arm and pinion shaft when you reassemble. Replace the o-rings on both sides of the pinion shaft