When they have rust on them or you need new ones. Go have them looked at
Sounds like low pads. many have built in wear indicators that squeal to warn you.
I believe your 4-Runner has an option of either rear drum or rear disc brakes. If the squeal is coming from the rear and you have rear drum brakes, have them cleaned and adjusted. If the squeal comes from the front, a shim may have slipped off of one of the brake pads and is scraping on the hat of the rotor.
You can try but the squeal will probably come back. Brake squeal is usually due to cracked, glazed, contaminated or inferior brake linings.
Are the rear brakes working normally?
in VW's when you have the breaks adjusted out too far they tend to grab when reversing. There is an auto adjuster in the rear drum to keep your rear brakes adjusting. If the brakes are worn out they will "hang up" after reverse and cause squeeling.
Well if its more of a squeal, your brake pads are probably low, and need to be changed soon. That will occur more likely if you have rear disc brakes.
Automatic transmission fluid does not squeal. You have a different problem. Brakes squeal, bearings squeal, and belts squeal. Fluids do not squeal. You had better take your vehicle to a mechanic.
There are a couple of possibilities. One is lack of lubrication of brake system moving and/or contact points such as between back of pads and caliper housing and/or piston. Another could be that, the rotors/discs are warped/distorted and need to be machined or more preferably, replaced. If you replaced the front brakes (example) and you still have a squeal, it's possible it may be coming from the rear brakes.
At least inspect when you hear squeal. Base further work on what you see.
Due to dust getting in between pads and rotor
first of all, the pads may be semi-metallic and have chunks of metal in them which may cause the squeal, change to a less metallic pad may help, also the backing of the pads should have an anti-squeal gel applied to them, when you apply the brakes, the pads will hyper vibrate and can cause a squeal. The gel will stop the vibrating. first of all, the pads may be semi-metallic and have chunks of metal in them which may cause the squeal, change to a less metallic pad may help, also the backing of the pads should have an anti-squeal gel applied to them, when you apply the brakes, the pads will hyper vibrate and can cause a squeal. The gel will stop the vibrating.
hypothisies