Knocking noise on braking from start up
Hi - for the last week I've noticed a faint knocking noise on start-up when i brake. It's almost like a slight delay before the brakes bite. i'm wondering if it's air in the brake fluid as once the car has warmed-up the knocking/delay goes. I've noticed the rubber seal on the cap has worn a bit but there's no obvious leak. The brakes work fine and it does seem temperature related as it disappears once warm. I've read in other posts suggesting drop links or engine mounts. Again, these may expand enough for the knocking to go away once the car has warmed up? We're going into winter here so it seems to be since it's getting colder!
Any help would be appreciated. My car is a 147 2.0 TS (2001).