Whoops, don't mean to start a panic on this but it is definitely an issue if you have one and lifted your truck without modifying it.<P>As for Gen 1's, I cannot recall if mine had one or not. It's pretty easy to tell if you have one. Simply lay under the rear axle and look at where the brake line comes from the front of the vehicle. Before the brake line splits to each rear wheel, look for a valve that is physically connected to a rear suspension arm or the axle housing itself by a metal link. <P>What it does is quite simple. The metal link changes angle as the rear of the vehicle is loaded more and more heavily - such as when you're packed for a trip. This tells the valve to proportion more and more braking force to the rear wheels. The default position when the truck is empty sends the minimum amount of braking force to the rear, which prevents rear wheel lockup.<P>If you lift the truck, the LSPV is sending the minimum amount of braking force to the rears. If you then load the lifted truck with 1200lbs of gear and people, the LSPV's sensing arm still says the truck is empty and the front brakes are getting an incredible heat load trying to stop the truck and added load essentially by themselves. Symptoms include front brake lockup or fade, warped front rotors, and rear brakes that won't lock up on gravel in extreme cases.<P>The cure is to look at the valve and understand how the linkage moves as the truck goes up and down. Then modify the valve's link so that when your truck is empty, the valve "sees" the axle as being located where it would be if the suspension were stock. For instance, on my 80 series the link is modified by bending it slightly with a pair of pliers. On others, you must extend the arm, and on still others you shorten the arm - study yours to see what needs to be done.<P>Remember simple geometry when doing this. For instance, on the 80 a 2 inch lift means something like a 1/8 inch change in the arm link location, not a 2 inch change. This is simply due to the angle of the sensing arm vs the axle. Study the way your particular model works to determine what should be done so your LSPV valve "sees" an axle in the stock position when your truck is empty.