I have a 1970 Cougar. It was the January 2019 Ride of the month.
I took it out Wednesday after its been garaged all winter.
It had a strong knocking sound coming from the passengers side front end.
When I applied the brakes it really got worse.
I didn’t have this with the old wheels that I had on the car but last fall I put new wheels on and it started then.
But the wheel spins freely when up in the air with no noise so Im not sure what is causing it.
Any help would be appreciated. I am going top get it on a lift probably this Sunday
Check the rubber insulators on the brake caliber bolts.
What kind of knock- is it rhythmic or random? A random knocking usually means something is loose. A rhythmic sound is usually something hitting or rubbing. Since it started with the wheel change, I’d focus on that. It could be as simple as loose wheel lugs. Or could be that the new wheels are hitting something when the suspension is under load.
Make sure all the lug nuts are tight.
If you find loose lug nuts, be sure to inspect the lugs, the nuts, & wheels for signs of damage. Make sure the lug nuts are the right ones for use on those wheels.
What diameter are the new rims? Sometimes 14" aluminum rims will interfere with the right front brake caliper. My American Racing Torque Thrust 14" rims did just that back in the day. I had to remove a bit of the outer portion of the caliper to clear the inside of the rim. Every once and a while a small pebble will get caught between them and momentarily make some noise as the tire rotates.
If you can put the old wheels back on long enough to take a test drive and see if the noise is gone that could determine your issue with the wheels I would think.