Situation: After a new set of brake disks are installed on the front brakes of the vehicle, they become warped and cause the vehicle to vibrate when the brakes are lightly applied. I suspect that there is a problem with the hydraulic braking system pressure equalizer. My suspicion is that the rear drum brakes aren’t even working and the brake disks are overheating and warping because they are absorbing all the braking energy. What do you think?
Find yourself an empty gravel lot and a friend. Have your friend stand off to the side and out of the way of the truck, and observe the rear wheels. Get up to about 5 miles per hour, slam on the brakes, and have the aforementioned friend tell you if the rears lock up or not.
I would think that it is more likely that the disks were not properly torqued and that warped them. Unless you are putting a lot of weight or towing a heavy trailer, the lack of rear brakes should not be coming close to stressing the front brakes. They handle most of the stopping effort anyway.
To check out the rear breaks I would just jack up one side have someone in the cab. Try rotating that wheel by hand and then have them step on the brake and see if you can still rotate the wheel.
Wheels were installed and torqued per specifications.