What would cause the steering wheel to shake when braking?

When was the last time you had brake work done? It sounds like the brake rotors cannot dissipate the heat from the heavy braking. If they overheat they can temporarily warp until they cool back down. I see this typically on rotors that were machined (sometimes still within acceptable limits) or from poor quality rotors.

Check the tie rod ends for wear. Have a friend rock the steering wheel side to side in the center and listen for a thunking or slapping noise at the rear of the front tires. Jack up the car in front and rock the wheel side to side (hands at 3 o'clock and 9 o'clock) and check for looseness.

Good luck.

One or possibly both of the brake rotors are out of wack and you need to replace them. I had the same problem on my 97 accord. I replaced the passenger side rotor and car is running and braking just fine.

Warped rotors. Get them lathed (Sp?) and don't forget new pads. If you leave the old pads on they'll wear grooves into the new(er) rotors thus making their life shorter and the problem re-arising.

A garage that my cousin had taken his '94 Buick Century to listed that it needed front struts, upper strut mount plates and inner tie rods. But after seeing these other answers here and helpful answers in other auto forums while researching in the mid part of April, 2005, my suspicions were confirmed that the shaking-only-when-braking on his car was caused by front brake rotor warpage (Although, later on, he also started to notice that when he put one finger on the steering wheel while cruising without braking, there was a very slight vibratory movement of the steering wheel...which I had summed up to just commonly being the brake pads resting lightly against the rotors even when no pressure is applied since rotor calipers do not have any type of return spring which would pull the brakes away any further). So just recently (4-21-05), against the "professional's" conclusions and $500.00 estimate (who had listed almost everything else but rotors as the cause), I put on all new front rotors and brakes (a total of about $51.00) and the car then braked beautifully with no vibration whatsoever. Vullin