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

  • 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:


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:

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

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.

Graph of Kawneer adjustment screw function

Picture of Kawneer Adjustment Screws


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)
Picture of Kawneer Adjustment Screw with new O-Ring seal installed

Kawneer adjustment screw with o-ring replacement


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 it’s 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

Pinion Shaft Illustration

Pinion Shaft Illustration

72 thoughts on “Door Closer Maintenance, Repair and Adjustment Info

  1. I bought an LCN traditional at a habitat for humanity restore… I am planning on repurposing it… and cannot get the end caps to budge. It pipe plugs with square 3/4 female ends. Any trick to getting them off. There is a ‘c’ cast inside the square hole. I don’t know much about these things. What would this model sell for?

  2. Hello Syl,

    dorma door swing, is this a surface door closer or concealed (in floor or above in the frame) the staying open on one side (does this door swing both ways (double acting) has this always happened or just started?? if its alwas happened, could be improper installation,

    if this is a surface mount closer, the closer was not mounted correctly according to the installation directions, if possible, can you leave a link to a photo (from photobucket or imageshack) of the closer your talking about??

    if this is concealed in top of frame or in the floor, (dorma BTS 75v or 80) there may be a problem inside and needs to be addressed by a door closer repair agency or locksmith who can get the closer rebuilt,


    sounds like the arm screw on top of closer body got loose, when it gets loose the closer will knock or rub it’s “elbow” on the top edge of the door when opening or closing, while opening and closing the door, tighten the arm screw on top of closer with a screwdriver, hope this helps

    -Jess the door closer doctor

  3. Hi – my hydraulic door opener is mounted to the door itself, with the arm attached to the door frame. The device has been working properly for over three years up until ~1 month ago. Now the “elbow” of the two arms is dropping about 1/2 inch after you close the door and thus it’s hitting the top of the door as it passes by the “elbow.” I can’t find a scenario like this outlined on YouTube – is there a simple fix for this issue or does it go beyond a simple adjustment and require new parts, etc? Thanks in advance!

  4. Replacing the oil after over-loosening adjustment screws on my Global (size 4) closer worked for me. I used some transmission fluid (ATF) I had lying around. To get it to work, I had to pour the fluid into both swing-adjustment holes, replace the screws, then pour more into the backcheck hole. Good luck!

  5. Nigel: I am glad that this article helped you out in getting your door closer refilled and working again, cooking oil can be used in a closer although not the best oil to use in one, but will still dampen the action,

    Dan Gelfand: I do not know the size for them off hand, but there are a few repair places that will repair the KAwneer closer, is this one a concealed “shotgun” or the old surface mount “storefront” closer??

    the shotgun (Kawneer Husky M-1 and M-2)type may be a bit harder to refill then the surface mount

    if you want to do this yourself, have you tried going to harbor freight to get a O-ring assortment kit??? refilling is same as the one on the article, if its the shotgun type (long spring tube, concealed in frame above door) its best you send it to a repair facility or locksmith for proper refill.

    the “shotgun” M-1 and M-2 if refilled the wrong way you could get hurt and/or make a mess of oil please be careful with it.

    hope this helps,

    -Jess the door closer doctor

  6. Just wanted to say this article was really useful. Oil had leaked out of one of the adjustment screws on my hydraulic door closer resulting in the door slamming hard against the frame. For a while I thought the only option was to purchase a new one which would set me back $60 (Australian). Read this article & followed the procedure on how to fill oil back in the fill port & it worked like a charm. Couldn’t get a hold of the hydraulic oil so I used some good old cooking oil .. LoL. Thanks once again for this post – very informative. As some one had stated earlier hardly any info or youtube videos available out there on this subject so this article is a great starting point.

  7. Re: Kawneer door closer:

    what size “O”rings are used on the two adjusting screws to contain the “oil”?
    thank you, dan gelfand

  8. Lynn whatley:

    the glass door, do you see any metal rectangular plates at top or bottom?? or any brands on the plates?? if the closer is RIXSON, there is an adjustment on the edge of door that can push door in or out (to drag ot not to drag)

    if its a DORMA, you will need to remove the coverplate and locate the alignment screws on ends of the closer body (they look like bolts) and shorten the ones farthest away from arm shaft the door sits on and lengthen the bolts on either side of the shaft that push against the back of the closer box the closer is placed in,

    if this does not work, the upper pivot bearing may be worn and may be best to have top pivot bearing replaced.

    Tom Bramhall: concealed closer in household/residential setting, is this closer located in transom on head jamb) or in floor???? this is not common unless its a care home or a high end mansion

    different brands have different spring strengths and settings, can you please tell me what brand it is?? or show a picture of the closer in question??

    Phil: door closer rebuilding is possible but may not be recommended due to the risk of injury to the person or more damage to the closer, you need special tools and the right knoedlge to perform it the right way,
    what brand of closer are you looking to rebuild??? there are a few rebuild facilities around the united states that are willing to rebuild it for you, and send your closer back to you. one popular place is New England Door Closer.

    Sunil: is this a closer similar to what Parod shows here on the website or is it one from 50’s (potbelly closer) different styles the refill process is different,

    if prefer to email me, JLD902 @ Aim. com, (remove spaces) theres only soo much a comment in a blog can help with, I hope I can help further if needed,

    -Jess the door closer doctor

  9. My door is closing too fast..Speed adjusment screw has become ineffective..Oil spills are visible outside.
    I dont know how to refill oil,if need be


  10. Can you direct me to ant possible “how to” videos /info on rebuilding commercial hydraulic door closers? Thank you- Phil .

  11. Residential style concealed door closer to hard to open for elderly client, I couldn’t find an adjustment for that. Any solutions ? Large wooden dble doors , one stationary , thanks!

  12. I am trying to determine how to adjust my commercial glass door with an automatic closer, where the door has begun to drag at the bottom. Any suggestions??

  13. Brian Beswick,

    easy one, sounds to me that your closer is in “freeswing mode” basically means the hook under the arm (that engages into the gear) disconnected by previous owner and not reconnected,

    to get it reconnected, disconnect forearm from closer (or the 2 screws that hold forearm to door) then swing the arm TOWARDS the hinge to about 45 degree angle, then put the hook in the notch on arm then push AWAY from hinges (you will feel a strong spring)and reconnect the arm,

    another way to do this is using a hook spanner wrench in the “teeth” of the gear on top to set the tension. when increasing tension of the “potbelly/traditional” closer, do not increase any more then 1 or 2 notches

    many people the old style closers choose to intentionally disconnect the hook from the gear when they want to have door open long term or like the style of the closer body but don’t need the strong spring to close it.

    I see this question all the time, I hope my answer helps with getting it to close again,

    -Jess the door closer doctor

  14. Hello to Walt, Casper and Sid


    if its possible, can you upload a photo of the door closer to a image host site (such as imageshack or photobucket and drop a link here?? (so I can identify the closer your dealing with to better tell you how to refill them)

    if they are similar to the Norton 1600 (such as the one Parod has on the article above, then it should be easy to remove from door, tilt onto end and remove valve and refill with oil,


    the closer you mention is the “shotgun” style OHC, (the closer is about 2 foot long) the area with the allen screws, yes, that is where the fluid is and the valves, if the screws were loose, yes, fluid can leak from this area, (just how did the screws get loose???)

    these closers are still rebuild-able by door closer service/repair centers. you may try to remove it from the head frame and back out a valve and rotate the shaft while putting in more oil (such as power steering or transmission fluid)

    when reassembling, make sure the 8 allen bolts are tight, you may need to use NON-PERMANENT threadlock (loktite) to help keep the bolts tight

    good luck with the “stout”


    what model is your dorma closer?? is it surface mount?? floorspring, transom(overhead concealed) closer?? most closers you can remove from door, back out a valve and refill with oil while slowly moving arm to work the fluid into the closer’s body. different models of closer it is different way to refill with oil,

    hope this helps,

    still need help??? can email me JLD902 @ Aim .com (remove spaces)

    -Jess the door closer doctor

  15. I have an old Lockwood closer ( No. 2184264 is stamped on the plate). There is a cylinder under the closer with a gear on top, it appears the piece that engages with the gear has slipped out. Any idea on how to re-install it? Or if that is the problem at all?

  16. Door will not adjust with any turn of screw. It slams shut all the way very fast. Not sure what model I have, but I will take it off door for further info. I think it might be completely out of oil.

  17. I manage an apt building have 7-10 doors with closers. I have 3 that aren’t working properly. I’m not too swift on closers. I like to investigate first and then get help before I attempt any repair. If I’m lost I get the repairman. Any help I could receive would be greatly appreciated. I probably have 2-3 different makes of closers.

  18. Hi I perform tech work for the overhead door industry as well as perform repairs and maintain overhead doors garage doors. On occasion I have a customer with a storefront closer or pivots that need attention. The one today is what appears to be one I haven’t worked on or seen it’s concealed and not as wide as the one most common global door systems is what appears to be no markings I just did a image search.
    What it looks to be. It’s real sloppy and slams. Has allen screws that looks to seal a reservoir, some of them screws were loose. You had much dealings with this model? Before I took it apart I just picked up a fairly normal concealed closer it’s to wide and I don’t want to cut out and fab to make it work. I see a fill hole for oil. I’m gonna attempt to service seal repair. It does not have hold open. Oh and it has like a short rack and pinion and a rather large chain link with master link that’s real short. Complaint is slams hard. Thanks

  19. Good day,
    ENCO is n maintenance capmany in ANGOLA jussing DORMA products.
    Am is the maintenance supervisor i want to know if we can refilling the door closer with
    oil.Maintenance Service and Repairs,
    If you can help my with Maintenance and service repairing Manuals/In Formycin will
    be helpful.

  20. Can a door closer, more specifically a floor door closer, ever build up pressure on the inside, especially if it is not in use, even if it has lost some oil? If they are not adjusted right where someone tries to force the door close, that would be the only situation where pressure would build up until the door is released. Love your feedback on this.

    PS: I have been learning how to install various brands of door closers on my demo doors and use the upmost care when I adjust them so everything works properly. I’ve paid for everyone of them and that is why I read the instructions very carefully before I did anything. I’m not lucky enough to have everything given to me.

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