My rear brakes make a thumping/wobble noise when medium/hard pressure is applied. In the beginning of drjve with light pressure i dont get any noise. I tried replacing my brake pads and no fix. Thinking maybe rotors next but dknt want to keep throwing parts at it for no reason. Any ideas?

 

First of all you appear NEW, so welcome.

It will be real helpful to put your cars details in your sig. It saves us constantly trying to work out what you got, or asking you each time.

Thumping from the rear is a rare one indeed. I am thinking a few things:

1) The rotors are worn down tooooo far.
2) The 2 pins that secure the caliper to the bracket are WORN in the housing, thus allowing the caliper to "bounce" around. That is NOT common, but I have seen it.
3) For some strange reason the ABS is kicking in at the rear when under your Medium/Hard braking.

Maybe other suggestions will appear from others as they come on board.

 

Oh, Sorry, it's a '96 XJ6.....

Thanks for the suggestions!

Im actually pretty confident its not the Rotors or pins now tha I've had a good luck at the brakes already. The ABS is an interesting hypothesis though.

Question: My dad was driving it and said he had bottomed out and banged the muffler and exhaust which dislodged them from each other. He said not too long afterwards is when he began to hear the clicking/wobbling noise from the rear brakes. We had another friend suggest the U-Joint may be bent/broken and it coming in to contact when car's weight is being going forward in one direction while slowing down.

Any other ideas....Ill be looking into it later this evening

 

NO.

I reckon rear wheels off, then systematically isolate items like exhaust hangers, shocker mounts, etc until something really looks/feels out of place.

The u/joints dont blip on my radar, they are huge strong bits and are the same as the earlier cars, and take a real pounding without too many reports of failures. The only thing with them is they require a grease application once a year or so, and I have yet to see one that has been greased regularly, and dry u/joints will certainly make some strange vibrations/noises/whatever, so maybe.

There are also lots of suspension locating arms back there, and his driving "adventure" may have torn the bush in one, again, not common in this model.