I've read about them here and studied the actual latch mechanism and am still a bit puzzled and still have difficulty getting the latch to operate smoothly. Here's what I see. As noted the latch actually is a double latch. One is the primary and one is a "safety" latch, just like on most cars today. I'm not sure why it has a "safety" latch, since the bonnet opens at the rear and it would not be a serious problem if the primary latch failed.
I think the primary latch is the one that catches the head of the pointy-tipped round rod. The spring that surrounds this rod pushes the bonnet up enough when the latch is released so you can get your fingers under the edge of the bonnet. This spring also creates some tension when closed so the bonnet does not rattle. I think this latch causes no problems, once lined up properly and lubricated with a bit of grease. Most of this discussion has been about getting this lined up properly.
The safety latch is the lever that projects up from the latch plate, shaped like the letter A with one leg removed. This latch catches on the metal bracket held in place by the same round rod as the primary latch. It is my assumption that when all is set correctly, and the bonnet is closed, this safety latch is actually not in contact with its mating bracket, but sets a few thousandths of an inch clear of it, and would only actually touch it if the primary latch failed. If the primary latch failed, then the spring would push the bonnet up a tad, to where the safety latch would then hold it "safely"
When the bonnet is closed, and the Bonnet handle inside is pulled, first the safety latch moves, and it moves easily because it has virtually no friction, since its normal closed postion is NOT in contact with the bracket on the bonnet. Then as the Bonnet handle is pulled further, the well-lubricated Primary catch releases the pointy headed rod and the spring pushes the bonnet up far enough to clear the latch and allow you to put your fingers under the edge of the bonnet to lift it up. This smooth, easy, action is what SHOULD happen, when you pull the Bonnet handle.
On my Alpine, the Bonnet handle is a bear to pull. I have broken both halves of the bakelite T from opening the bonnet. I am 99% sure the problem is that, when the bonnet is closed the safety latch is in contact with (and under tension from) the bracket on the bonnet. I've done some bending of the bracket and adjusting of the pointy rod, and it's better. When it gets warmer out next Spring I'll try some more.
Does this description match other's understanding?
Tom
