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
- Hydraulic Door Closers close a door automatically at an adjustable speed.
- A Door Closer is usually mounted at the top of a door or above it on the jamb. There are also internal models that are installed hidden inside the door frame for a cleaner look.
- An internal Spring applies force to the Arm to close the door. Hydraulic fluid (oil) flows through pathways inside the closer. The resistance/restriction to fluid flow determines the door closing speed.
- Spring strength and adjustment (if any) varies by model. Heavier doors require stronger door closers.
- Door closers are matched to their application, based on door size and weight, and the corresponding strength needed to close them properly.
- Adjustable Spring tension allows models so equipped to work well for doors of sizes within their range of adjustment.
The operation of a door is controlled by the Door Closer in 3 basic zones:
Adjustment
Instructions here are for a properly functioning door closer. If your door closer is not functioning properly, see Troubleshooting section before adjusting.
- Adjustment screws usually require a hex wrench.
- Your closer may have a cover that must be removed before you can access the adjustment screws.
- Do not unscrew the adjustment screws, they will fall out, and oil will spill!
- Generally, turning a screw Clockwise will increase resistance or slow the door, Counter-Clockwise will do the opposite.
- Adjustments can be sensitive, start with a 1/4 turn
Adjustment: Things to consider
- I prefer a slow-moderate sweep and a slow, quiet latch. Sometimes environmental factors do not allow an ideal adjustment.
- If your door won’t latch when adjusted to a slow latch speed, perhaps your latch bolt is not functioning smoothly or installed correctly.
- Perhaps your door requires a higher closing force, adjust your PA (power assist) or Spring Tension if available
- Variables to take into account:
- Weather conditions: Wind, Snow, Ice, etc. You may need to adjust your door to close properly across ALL conditions
- HVAC: Positive or Negative pressure in your building. Some ventilation systems will cause the door to blow open or pull shut, you may need to adjust your latch speed to a little faster to overcome a positive pressure, or slower to handle a negative pressure.
- Your latch zone may be lengthened or shortened by adjusting your arm length.
- Adjusting your arm length may also cause your max open angle, or backcheck zone to engage earlier
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:
- Sweep speed (and Power Adjust if necessary/applicable)
- Latch speed
- Backcheck
Picture of Norton Adjustment Screws
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.
Picture of Kawneer Adjustment Screws
Troubleshooting
Most problems are caused by low oil.
Low oil level can look like:
- Door swings too fast to a point mid-swing, at which it closes at a normal slow pace
- Door swings closed without any resistance, slamming against door jamb/frame
- Changing adjustment screws is of no effect
- Oil puddle underneath door closer unit
- Oil drops on bottom of arm
Oil loss is usually due to:
- An adjustment screw being removed
- Leaking adjustment screw seals (o-rings)
- Leaking arm shaft seals (o-rings)
Kawneer adjustment screw with o-ring replacement
Repair
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
- Wear Safety Glasses
- Note the leaks, and their apparent origin
- Remove the door closer unit from the door or top jamb
- Move unit to a suitable workspace (oil will drain, and sometimes squirt from unit during refill process)
- Remove adjustment screws or other hardware to gain access to seals
- 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
- Typical: re-insert BC adjustment screw, tilt and hold closer so that it’s on it’s end, with the S and L adjustment screw ports facing upward
- Fill port(s) with oil, slowly moving the closer Arm to distribute oil internally. If you move too fast oil may squirt out!
- 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
Pinion Shaft Illustration
8 Comments on "Door Closer Maintenance, Repair and Adjustment Info"
Thanks a million. I was in building maintenance for a couple of years, filling time before retirement, and looked high and low for this information. I’ve noticed a couple of buisnesses that need help with there doors. This will be of great help.
Thanks again
Ken
How do you fill the old Kawneer door closer with oil? Where is that done? Also what size o-rings do I need to replace the old ones? Thanks in advance, Randy
This article is very helpful. We appreciate very much !
Do you have info on adjusting/repairing a Parker hydraulic closure?
With the closer removed and on the bench, I removed the combination swing/latch adjustment screw and put the oil in that hole.
Sorry, I don’t remember which size o-rings were needed. If you take the old ones to a hardware store they can find some equivalent ones.
Thanks for the question!
Sorry, I don’t have Parker-specific instructions, but the general ones may work for you. Let me know what you find out and I’ll update the article.
Thanks for your question!
hey parad, I recognize some of my tips used here in the updated site, glad i was able to help with troubleshooting of door closers (i emailed you using gmail instead of aim)
cowboy, your parker, do you have model number??? does it look like any of the closers pictured in the article parod has made??? many closers are generic spinoffs of name brands and basically can be fixed the same way as name brandwhen replacing seals,
many newer closers (Norton, Yale, LCN’s some have an indention near the valve hole that prevents valve removal from beyond body surface. if you really must remove the valve, its best to use a dremal and file down the indention so it looks like there’s no indention, you may meet resistance when removing the valve after this, it’s because of the tight fit of the valve against the shaved down indention on body when removing the valve screw
if working with the LCN “no leak” closer, their O-rings are alittle different, they are some v sheild thing, as in part gets moved across 2 “wipers” (much like a car shock absorber)
now if the leak is from the end cap (part with 2 or 3 holes, or huge cross head screwdriver bit depending on the brand and year they made the closer in, the O-rings for the end caps usually are thicker and larger in diameter and because the spring in many closes is under compression even when arm don’t move (rest position) and closer is off the door, its best if you have a machine shop or locksmith shop remove the effected end cap(s) to do the O-ring replacement, being they could use a press with the oversize bit and not risk injury from a spring flying out.
Mr. CParod: im glad we can now comment on this and get/give help with door closer repairing. great job on updating the door closer repair info page, if you come across any problems with ones you fix, please let me know as well, ok cparod???
I was given the nickname door(closer)doctor in high school because of stuff like this
adjusting and telling maintenance men how to fix leaks and once in a while fixing leaks and gurgling sounds some may make due to low oil.
-Jess the door(closer)doctor
Thank you this was real helpful.