When your sliding glass door doesn’t cooperate, it’s time to break out the tools. With latching and locking problems, you need to look to the handle and latch assembly. The handle has an integrated latch that mates with a “keep” on the door frame. The keep looks somewhat like a hook and can be adjusted by two screws. This holds to door tight to the frame and keeps the opening secure.
If you have to push hard to get the latch and the keep to align or have to push on the latch extra hard, you might benefit from a simple latch assembly adjustment and maybe some lubrication.
With the door open, cycle through the locking mechanism at the latch several times. It should easily move into the locking position. If not, use some spray lubrication and spray the moving parts inside the opening and again cycle through the movement to spread the lubricant around.
Now partially close the door and extend the latch. You want to make sure it is properly aligned with the keep on the jamb. If they are slightly off, slightly loose the keep and move it up or down so that it mates perfectly with the latch assembly.
Although you may not have a keep that looks like a hook (it may look like an opening on the jamb), you will still be able to adjust the latch/keep for easy locking.
Sometimes getting your sliding glass door to open and close takes raw, brute strength. Your door can certainly be improved with a little tuning up...If you clean, straighten, and lubricate the door, it will slide much easier.
The track of the sliding glass door is where years of nastiness builds up. Dirt and oil combine to make a sludge that can get into the doors wheel bearings and cause them to break down. Sliding glass door rollers are not always metal either, some are made of plastic.
Use a small standard screwdriver and scrape up all of the sludge in the track. Then use a clean cloth and wipe up any remaining remnants of dirt. You will need to move the door back and forth to get access to the entire length of the track (assuming you aren't removing the door). Once everything is nice and clean, check to see that the track is in good condition. If the track is bent and rubbing on the door as it moves, use a block of wood and a hammer and tap the edges back into place.
The sliding glass door rollers can be adjusted for height using a screwdriver. At the front and rear edges of the door are holes that allow you to insert a screwdriver in them. Inside the holes are screws that raise and lower the rollers. Adjust the rollers so that the door is level and not rubbing on the track. If you are considering replacing your rollers, read this article on how to replace sliding glass door rollers.
Once the door is level, you can use a graphite or silicone spray to lubricate the rollers. I would avoid using WD-40 as it tends to attract dirt and will shortly gum up the surfaces.
Yesterday we went to repair a customer's sliding glass door. He said he was tired of fighting with it to get it to open. When he called in we told him it we would need to get the correct rollers for the bottom of the door, take the door off, and be done within a couple of hours.
When we got there and looked at it, sure enough you had to throw your shoulder into it to get it to budge. However, the track was filthy. It was covered in dirt with a layer of dog hair mixed in for good measure. Instead of the cost of replacing the rollers on the bottom of the door, we first tried to clean the track. This was pretty disgusting but effective.
Fortunately, the existing sliding glass door rollers were made of metal (some are actually plastic). So after the track was cleaned, we lubricated the rollers. I'm happy to report that the door is as smooth as butter.
Of course, the homeowner watched everything we did and decided to tackle the other door by himself. There is that old saying, "If you give a man a fish he can eat for a day, but if you teach a man to fish he can eat for a lifetime". I'm guessing he will maintain his sliding glass door by himself from now on.