Like others have mentioned before, WD40 is not a great lubricant.
Is great to clean the parts and remove some rust, but afterwards you should use a better lubricant.

Many recommend a silicone spray, which is what I've used on mine and I only have to apply it 1 or 2 a year.
Living in the Rust Belt, I try to apply it once in the fall and another time in the spring.

The silicone spray is also great for all the rubber seals around the doors & hatch, which I also do in spring & fall.
And also inside the window tracks, which I only apply 1 / year.

 

Thank you Black3sr, but my Honda Fit is an older model and doesn't have the "safety release lever." There's only a small access hole inside the rear hatch. Other online sites suggest pushing the metal lever to the right to release the latch, but unfortunately, nothing happens and it's still locked tight. If anyone has a suggestion on what to push, pull or prod with a screwdriver, I would be most grateful.

Maintenance access hole is extremely small

 

My '09 Sport (75000 km) just did the same thing: doing some multi-stop grocery shopping and hatch worked fine at first stop but refused to open at the next store. Mutter, mutter!!! My issue was on the handle area as it felt like it was in the "open" position" and had no movement. Thanks everyone for the hints, a couple of shots of Fluid Film (similar to WD40 but without the water content) and it seems to be working OK. Fluid Film, I think, is available at Canadian Tire, probably NAPA, etc.

 

Good video here going to lube my stuck latch today on my 2013, hope it works but glad I have easy access with folding seats ....insert wink.

 

Has anyone in salt country tried to replace the latch handle? I tried it and found one problem. You have to remove the tailgate lower trim panel. This is the big plastic piece on the interior side. Then you have to remove the rear license trim. This is the plastic piece on the exterior, above the license plate, and with the Honda logo in the center. To remove this trim, there is a metal bolt on the left side of the logo with a square nut that is seized onto the bolt, so the nut and bolt turn together. This is bad. And, of course, the trim design makes it impossible to get a tool in there to hold the nut. If you use a torch, you will melt the trim. Any ideas?

 

Don't know about the procedure involved in replacing the mechanism but for seized nuts/bolts a shot of Liquid Wrench should do the job — NAPA etc should carry it. Also, have you tried Liquid Wrench on the latch itself? Squirt up between the license plate lights — may save you from having to replace the latch.

 

The latch is very rusted and needs to be replaced. A gallon of liquid wrench or any other lubricant won't do much. The problem is holding the nut. It is in a very tight cubic-type space, so no standard tool will fit in there. There's probably 1mm of space between the nut and plastic. Even needlenose pliers are thicker than 1mm and they're angled..

 

Penetrating fluid, torch, impact, or drill it out.

 

I just got some CRC Freeze Off to loosen the emergency brake levers on my wife's Accord and it worked well. Got it at an Auto parts store.
https://shop.advanceautoparts.com/p/...5002/7080144-P

 

This thread is five years old so not much help now. Whenever asking questions on the forum, you should identify your year and model. Since you said you only have a small hole on inside trim panel, you probably have a 2007-2008 model. It's about the size of a silver dollar. Later models have a much larger rounded rectangle hole. Move the lever towards drivers side to release the latch.

 

Go here and scroll down for pictures to lube handle mechanism . https://www.fitfreak.net/forums/2nd-...le-sticks.html . Do this every month or so .