|The MGA With An Attitude
Dealing with a STUCK BONNET LATCH - BD-101A
At 11:15 PM 12/4/2006 -0500, Bob Figenskau wrote:
>"The latch does pull, but we have no release. Any suggestions are welcome."
The most common cause of stuck bonnet latch is a misaligned latch pin. The pin has a tapered nose and large shoulder. When a misaligned pin is forced through the guide plate it will bend off center a bit, then snap back straight to have the shoulder caught beneath the guide plate. The hole in the bottom guide plate also has a short extended wall on the side. If the latch pin is adjusted slightly long as well as being misaligned, and the bonnet is pressed down with vigor to over-travel a bit, the shoulder on the pin could be caught below the short wall on the bottom guide plate.
The first order of business is to recruit a helper to pull and hold the release rod while you fiddle up front. Or you can pull the release rod and secure it in the drawn position with a pair of locking pliers (ViceGrip) against the back of the bulkhead. If interference of the latch pin is not too great, sometimes you can press down on the bonnet and release it suddenly to get it to pop up (but don't count on it).
The solution to releasing the latch depends some on the direction of misalignment. If the latch pin is a bit too far forward you may be able to stick a thin metal rod through the grille to push the pin back enough to release. If the latch pin is a bit too far back a hook formed on the end of a metal rod may work to pull the pin forward a bit. For a few minutes of work you can make a special tool for all occasions. Weld a flat washer on a steel rod about 30 degrees out of plane from the axis of the rod. With this you reach through the grille to capture the tip of the latch pin and pull or push or nudge in any direction to unhook the shoulder.
The latch release draw rods are connected with a cross drilled bend on the end, a flat washer and a split pin. If perchance one of these rods should become disconnected, your problem is much more challenging. This too requires access through the grille slats, and it helps if you understand the orientation and operation of the latch release slide. As you are facing the car from the front the latch release slide must be pulled to the right. With some luck and proper finesse a thin rod with a hook on the end may work, if you can find enough clearance between the grille slats to reach in at an acute angle from the side. Or you may try a 1/8-inch (3-mm) flat steel strap, slipped through the grill slats from the other side to push on the release slider near the spring attachment point. If this approach fails you may end up doing substantial damage to the grille by the time you gain enough access to affect the bonnet release.
If you have been doing restoration or paint work, and the bonnet is being installed for the first time, do be sure you have the latch working properly before you install the grille. Also check the condition of the split pins and washers on the draw rods occasionally to assure that they will not fall off from normal wear after many years of normal use. As an emergency backup, some people go as far as to attach a piece of small cable to the latch release slide and run it through a drill hole in the inner fender with a pull loop behind the headlight.
Addendum, Nov 2010:
Cam Cunningham in Lancashire, UK offers this trick.
"The answer to the broken bonnet latch is to change the mounting bolts at the top. Instead of screwing the bolts in from underneath the bonnet, fit longer ones to the top of the grill first and then slip a polythene sleeve over the end (cut from a length of plastic pipe). This means the grill can then be pushed into place in the bolts holes first (the plastic stops it rattling) and then the bolts at the bottom fastened. Now the grill can be removed easily without opening the bonnet".
Addendum March 3, 2012:
If you have small arms and plenty of patience, Larry Benson in Greenback, Tennessee, USA has this suggestion.
"Remove the three bolts (from under the valance) through the radiator panel securing the lower part of the grill. Gently raise the lower part of the grill to allow insertion of a slender arm between the grill and the body. Feel for the location of the three upper bolt heads holding on the upper portion of the grill. Remove arm and place 7/16 open end wrench in hand and reinsert hand with arm still attached. Tediously unscrew bolts holding upper portion of grill. Remove grill and then do whatever is necessary to release the hood. I had to do this twice, before I realized the SPACERS on the hood bracket mounted on the cross-member were too short, preventing the hood release rods from actuating the hood release mechanism. No damage to grill. I also managed to undo the guide plate hood bracket on the cross-member with the same 7/16 open end wrench with the grill attached, but it was very, very tedious and frustrating".