With a broken fender brace in your engine compartment, the support for the top of the fender and the radiator is diminished. By being in the engine compartment, it is not too susceptible to rusting, but can easily be damaged if there is a front impact with a hard object. The fender brace can also be damaged by a technician that places excessive weight on it when working on the vehicle. This support component is made to withstand forces laterally and not vertically while in place on the vehicle or front to back and not top to bottom. If bent, the radiator will not be able to be positioned correctly.
The material a fender brace is made from is a steel alloy that is pressed into shape with several ridges. It is the ridges that give this support item its strength and helps to prevent it from bending when a force is exerted on it. The fender brace is located with one end on the top of the front wheel fender with the other end on the radiator mount. It was designed to provide strength to the front end in case of a head on collision. This would slow the crushing effect of the impact so less damage would occur to the passenger compartment.
There are two fender braces on the front end of older vehicles. Once the hood is up, the braces would appear to be in the formation of a giant v over the front of the vehicle. By removing the bolts in just one, it can be safely and easily replaced. Then the other fender brace can be removed and replaced. Do not remove both of them or the alignment between the radiator and the front fenders could alter and be difficult to place the new components on the vehicle.