The load sensing valve is by the rear axle. It's a proportioning valve that adjust the rear brake fluid pressure based on the difference in height between the axle and the bed of the truck, which will vary depending on the weight of the load in the bed. It "could" be bypassed, but it will affect the brake performance when the bed is weighted down. If you drive around with a light load or empty most of the time, you probably won't notice the difference. I'm showing a part number of 46400-32G00 with "limited availability," which often means if it's not sitting on the shelf at someone's dealer, it's not available. It's also not cheap with online prices around $320 and an MSRP over $400, but cost is irrelevant if you can't find the part! Salvage yards might be the only option if you can find one that's not all rusted apart.