I have a 1998 Dodge Ram 2500 4x4. I do not know much about how the brakes are supposed to be on, but I can actually grab the whole caliper system, and move it slighty. Up and down. Arent they supposed to be completely bolted solid?

My truck is also making a rattling, especially when I coast at speeds below 30. I did hear it today on the freeway at about 50. It stops as soon as I apply the brakes. Itonly seems to do it once the car "Warms up". If I accelarate quickly, it wont do it until I slow down.

Larger tires were installed on this truck before it was sold to me, according to the seller, it did not make this noise until the biger tires were put on.

Are these two possibly related?

I really appreciate any advice.

 

All calipers are made to slide (slightly) along the installation bolts to adjust for pad wear. In fact, that is how you get them off the rotors, by using a clamp to squeeze the calipers and loosen the residual force holding the pads against the rotor. Then the pads may alsodevelopa little as they wear, but many have some sort of clips to keep them in place.

But a noticeable rattle after you have driven it around and tried braking it does not sound right. One possible causeis a little warpage in the wheel causing the rotor to not seat square on the axle... the rotor wobbles the caliper and/or pad making the noise.

But before you go down that path, start with the simple stuff by a complete maintenance on your brakes.

edit: I reread your post... and I have this to say: replace your pads

 

I had something similar. I put hundreds if not close to a grand in parts and labor trying to chase down the issue. Although I'm sure I replaced worn out parts that could use to be replaced, all it ended up being was a set of junk pads from Autozone. I'd start there since it's easy and pretty cheap than thinking big and replacing really pricey parts.