Warped brake rotor. Have the rotors removed and trued or replaced. Replace the brake pads at the same time.
If it shakes all the time it is a tire/wheel problem. If it only shakes when braking then it is a brake problem.
Warped rotors
It is likely a brake rotor has to much run out (warped). There could also be some problem with steering or suspension components.
You need an alignment.
You need the front rotors machined or replaced.
if it shakes while your braking your front roters could be warped or if it shakes while your driving try balancing the tires at a tire shop.
Your AC should have NOTHING to do with your barking system, as it is not tied into the vacuum of the engine. If your wheel shakes under braking, then you need to replace your rotors and pads.
The braking problem is almost certainly a disk brake rotor. The vibration could be a faulty tire, a bent or damaged "half shaft" or an out of balance tire. Front end vibration is not caused by an alignment problem, but can be accentuated by worn suspension or steering components.
there could be several reasons for this problem the most likely being an alignment problem, if it occurs only when your braking it is probably warped rotors or out of round drums depending on your braking system bad spark plugs or wires
1 of 2 things or both, alignment or balance.
check your tires for a belt seperation. check steering stabilizer shock if equipt. if braking, check for warped rotors.
roters need turned. 65;