92 explorer, 4x4, v6 4.0 litre (~~240ci's)

shakes when i brake. shaking slows down when vehicle slows. shaking can also turn to slow knocking when i brake and i almost think i can feel the brake pedal giving with the knock.

could something have gotten caught inside that would have put one out of place.. ie not parallel with the wheel cuz shaking sometimes turns to knocking on only the one side when you apply the brakes hard. my guess is one disk is so out of whack that this causes the shaking but the occasional knock is some kind of safety release mechanism when the disk turns to point where it is too close to the brake pad.

if i need to replace the disks on my explorer but can't afford to go with new ones. any advice on how to diagnose the longevity if i get them from the scrapyard?

can i use a tape measure to measure for the manufacturer's recommended thickness. i know my mom had the disks planed more than once cuz they were too small for the weight of the car so i don't want to buy some used that are no good any more.

can u tell by looking across the surface if disks are warped? the service station said they were warped by excessive braking that heated them but i kind of doubt this story?

 

Our Explorer shook & knocked. Inspection revealed that the bolts holding the spindle and backing plate/hub assembly together were loosening. Blue Loctite(TM) and judicious tightening with the wheels off the ground took care of the problem. As to junkyard brake rotors--I don't think you'll be able to check thickness with a tape measure. Instead, try to borrow a caliper from one of your neighbors or friends. Warpage is another problem that's difficult to detect with the naked eye--a dial indicator setup is usually required. Good luck.

John

 

we had a 350 dodge van that shoke when ever the brakes were applied.no one liked to drive it cause it was a piece of #$@!.
so we traded it in for a chevy van.

but I would check the U-joints on the drive shaft and make sure the brakes aren't locking up.

 

[updated:LAST EDITED ON 11-Mar-02 AT 08:46 AM (EST)]I suggest that you don't skimp on the rotors. For the first year we owned ours, I thought that the vibration was normal. Then I replaced the rotors, bearings and pads. Then it drove like a new truck, like butter. Then after some time, I had to turn them. The result was not even close, now it sounds like a mild grinding, even though I have checked everyting. The severe knocking you have is possibly another problem that is brought out by your warped rotors.

 

You have the same problem that I had on my 94 Explorer. The front rotors need replaced with new ones that you can get from PepBoys for about $140.oo a set. Take the wheels off the front and look for a crack or cracks along the outer edges of the rotors. Small cracks will flex open just enough to chip away at your brake pads during braking and make the knocking sound. Maybe your steering wheel shimmys just a little bit also when braking?!
Don't skimp on buying new rotors as ones from the boneyard will probably cause problems also. You shouldn't mix the bearing races from one vehicle and another because they have worn together as a pair. If you can afford it....replace bearings and innner dust seals and apply a good application of new bearing grease.
You won't regret it either.

Keith