durandetto

There's a good chance it's the water pump gaskets. Very common and you'll almost never see a leak on the ground, because it burns off on the block.

Start the truck and let it run for a min then shut it off. Wait a min or so then pull the check valve out of the booster and see if there is still vacuum. If not you probably have a leaky booster. That's not a common issue on these trucks but neither is the problem you're having.

You probably wouldn't hear the check valve inside the truck.

The hissing could mean a leaking brake booster if you have a vacuum booster.

Fronts don't require much caliper bolts are 19mm bracket bolts are 18mm and if your changing rotors you'll need a small torx bit not sure the exact size though. 15 maybe. Rears depending on the year requires different tools. The first design can be done with a pair of side cutters and needle nose vice grips, at least that's how I do them and it's much easier than the special tool they make for it. The second design you'll need a set off drum brake tools or at least a hold down spring tool.

Have you checked your ac belt yet?

Maybe try a big punch and a hammer to try and spin the bearing in the knuckle them use the slide hammer. You need to break the rust between the bearing and knuckle for it to come out. Pull the bolts and strike on the ears of the bearings where the bolt holes are.

Installed thousands of these shocks and that's how they are. No need to worry just make sure you get them centered on the hole.

Slide hammers don't actually work as good as an air hammer. You need to spin the bearing in the knuckle to get the corrosion to break loose. If they are really bad you can use torches to heat up the knuckle by where the caliper bolts up.

At my shop we use Amsoil and I wouldn't put anything other than that in my vehicles.

Exhaust leak before o2 or faulty o2.

Possibly a u-joint. Pull your driveshaft and see if they're binding.

Dexron VI is synthetic and is good for 100k. Do not put III in it. It probably wouldn't be a bad idea to change it every 50k, but you don't have to.

As far as bearings go, Timken would be the best. They have a lifetime warranty and hold up really well compared to others.

Try tapping lightly on the axle housing where the actuator screws in. Mine was a pain to get out as well but with a little vibration and a lot of force it came out.