This is a fairly in-depth question, it could be 10,000 miles to 100,000 miles. It all depends on what kind of brake pads/rotors you currently have, what your braking style is like, whether your miles are mostly city or highway, and if the load in your van is heavy or not.
Are you heavy on the brakes, do you ride the brakes, or are you good with them? City miles involve more stopping and starting and thus more pressure on your brakes whereas on the highway you could go for miles and miles without ever touching them. Is your van full of kids or hockey equipment or what have you? The heavier the vehicle is the more pressure it takes to stop it and the harder/longer you have to hold the pedal down.
Whenever they are warped, damaged or worn down to the minimum limit. Your local auto parts store can measure your rotors if you bring them in off the car.
It's PROBABLY warped disk brake rotors. Brake rotors will warp when overheated and if you go downhill very often, they've probably overheated. Replace the rotors with a high quality product and they'll last longer.
when there is a visable rigde / lip on the edge of the disc (rotor) when there is a visable rigde / lip on the edge of the disc (rotor)
It is recommended to rotate brake rotors every time you replace brake pads, which is typically every 30,000 to 70,000 miles, to ensure optimal performance and longevity of your vehicle's braking system.
Almost never-- unless you have a E-brake dragging due to a stuck cable or a brake calipher dragging. If this is the case you will burn out rotors one after another.The E-brake cable should return to the full off position and the calipher should retract fully. I hope this helps you. Mark
What you're describing sounds like "disk brake chatter". It's a condition caused by warped rotors. Rotors often warp when they're old and/or have been overheated.
Disk brake rotors will warp when the overheat. Riding the brakes, a lot of downhill or other heavy, continuous braking can result in an overheated rotor which can cause brake pulsing. Some call it 'brake chatter'. Often the rotors can be "turned" to make them even again, but if the rotors have worn down already or if the manufacturers specs have been exceeded, turning won't be an option and you'll need to buy new rotors. You can't inspect them to determine if they're warped, but if the vehicle has brake chatter, the rotors are warped.
They need replaced when they wear out.
Rotating brake rotors should be performed every 15,000 to 70,000 miles, depending on the vehicle and driving conditions, to maintain optimal performance and safety.
Remove the brake rotor and have it checked at a reputable auto parts retailer. Rotors often warp with age, especially if they have been overheated.
Every 2 years
There will come a time when you have to replace your rotors. The rotors are an essential part of your car’s braking system, as the brake pads grab on to the rotor, using friction to slow down and stop your car. While rotors do not need to be replaced as often as brake pads, they still require regular servicing in order to remain an effective part of the braking process. There are plenty of reasons why you should have your rotors replaced. One reason is that over time, rotors can become suspectible to developing grooves and gouges, especially if brake pads are not changed in time. As the brake pads wear, there is a greater potential for the pad hardware to come in contact with the brake rotor. When contact occurs, deep grooves can be scored in the surface of the rotor. Eventually, the rotor will have a number of deep grooves that can interfere with normal braking. If you can feel deep grooves in the rotor surface with your fingernail, then your rotors need to be replaced. Warping from excessive heat can be another reason for replacing your rotors. Rotors are also tasked with dissipating heat that is caused by the friction of the brakes. When the rotor material becomes too thin, the rotor can lose its ability to channel heat away from the brakes. Excess heat can cause the rotors to warp, leaving what should be a perfectly flat surface looking more like a warped paper plate. The warping is minute to the naked eye, but it often presents itself as excess pulsation when the brakes are applied. Rust is also another reason to replace your rotors, especially if you have a vehicle that has been sitting outside for a long period of time. As the rotors are kept exposed to the elements without the benefit of friction keeping the surface clean, surface rust can develop on the rotor. Rusted rotors are definitely not as effective when it comes to stopping a vehicle.