Strange knock under braking

[AshM]

Wanted some advice please.

Long drive South today from Edinburgh down to the JEC Summer Festival at Gaydon. Car flying along, all fine.

It then developed a strange scenario under braking. When I pressed the brake pedal there was a mechanical feeling - a knock. Both under my foot and could hear it too.

I could brake ‘through it’ - that means if I carried on depressing the pedal it stopped.

Braking performance itself not impacted at all.

After a while (45 minutes, 50 miles or so) it disappeared.

Apologies for the rather strange description. Hope it made some form of sense.

Any thoughts?

Cheers
Ash

[mgcjag]

Hi Ash...iv had similar in my daily driver.... Stone got jammed against the disc and back playe but then threw it put...if it all sounds and drives OK now then possibly something similar....Steve

[caveman]

It could be brake pad rattle/chatter, do you have anti rattle clips on your brake pad pins?

[Jack the lad]

Hi Ash, has your car been stood for a while? If so it could be a rusty disc, surface rust forms on the discs except the small area swept under the static brake pads. As you use the brakes you get a bit of a knock until the rust is worn away. Depending how rusty they are could take about 30 miles, also depending on how heavy you are on the brakes. cheers John.

[AshM]

Thanks all, I appreciate the replies.

I will give the car a good inspection this morning to be on the safe side. But it appears to have remedied itself so I think Steve’s theory may be correct.

Thanks again.

Cheers
Ash