I had my tires changed a while ago. After the change there was a very loud knocking coming from the rear of the car which correlated directly to the car's speed and disappeared entirely when the brakes were applied. I brought the car back to the tire place, after much examination it was determined that the right rear brake pad was loose. After this was tightened the noise seemed to disappear. But a couple days later I notice a distinct but not nearly as loud knocking coming from he left rear. Brought the car back but the the right hand and left hand at the garage weren't talking and instead of tightening up the brake pad (which I'm assuming is the problem) the guy didn't know what was going on and tightened the calipers and goodness knows what else. This solved the problem for about 10-15 minutes then it started again. I am having zero braking issues.

My questions:

1) What are the chances this is actually another loose brake pad?
2) What are the risks associated with a loose brake pad?
3) I am fed up with going to the garage that I've been going to, they are okay but the hours are short so it's tough for me to get the car there. How long would tightening a brake pad normally take?
4) How the heck would this even happen?

Edit: 2006 Base Mini.

 

Changing the tires shouldn't have anything to do with the rear brakes. There is also no way to "tighten up a brake pad". Either the caliper is loss or tight. Do you know how much wear is on the pads? Have you tried jacking up the rear and spinning the wheel to try to pinpoint the noise? I am in the process of doing a rear brake job on our 2002. Waiting on the machine shop that is turning my rotors to put back together. Interesting is that this Mini has no wear sensors and my wife told me the rear was making a noise and sure enough metal on metal.

 

Thanks for your reply. I brought the car back to the garage and whatever the guy had to do to make the knocking disappear he did. It concerns me a bit now mind you, particularly since I just sold the car.

The brakes were done in August of last year, they were perfectly fine until I had the winter tires swapped out for the summers and then immediately the knocking started, first in the rear right then in the rear left. The brakes worked fine and there was no grinding, no squeaking, just knock knock knock, faster or slower depending on the speed of the car. In term of wear and tear, probably less than 10,000 km.

 

The only thing I can think of is the rotors are held on by a star bolt. I know our Mini was missing 3 and when I did the rear brake job I had to drill the one out. If somehow they rotor was cocked a bit when they put the wheels back on the rotor could make that noise. But hard to say without having a look at them.