Shock problems after new brake pads?

I took my '02 Hyundai Elantra (84k mi) in to replace brake pads. When I got it back, I was bouncing down the road. Every bump sent me oscillating like a slinky, and it seems to be mostly driven from front left tire. I found they had filled tires to 40psi, which I promptly reduced to 32, but found the problem persisting.



I attempted the ‘bounce test’ and couldn’t really even get the front end to move appreciably to see if it continued oscillating. Back end worked fine, just as described, with only 1-2 cycles before resting.



I assume it’s the shocks going out, but what are the odds of it coinciding w/ brake service like that? Service dept. said there was nothing they did that could have caused it. Don’t know what they could have done, but just seems too coincidental for comfort. Is 84k miles good/bad/avg for replacement of shocks/struts? Is there anything they could have done to cause this?

When they did the brake service, they put the vehicle on a lift. When they lifted the vehicle it allowed the susprnsion to hang, hyper-extending the struts. If the valving in the struts is marginal from normal wear, lifting the vehicle can show how worn the valving is and you end up with a ride that’s not as stable.

If the struts are good and you lift a vehicle this doesn’t happen. But if the struts have miles on them, lifting the vehicle can reveal how worn the struts are. So don’t go back blaming those who did the brake job. They did nothing wrong.

Tester

About the only thing they could easily screw up that might produce your handling problems would be to forget to tighten the wheel lug nuts. Not very likely, but worth checking because loose lug nuts will probably get looser, a brake rotor may wobble and end up warping, and a wheel might eventually come off.

Thank you for the prompt and thorough response. I’m guessing my prognosis is another service job, this time focused on the suspension…