Got a hard one for you guys.

ok, I know this is a chevy forum, but the GMC forum aint too active. I own a 99 GMC Sierra EXCab, 5.3L. I have recently gotton my brakes worked on, rear drums replaced, new rotors, new pads in front. I have noticed a knocking sound coming from my front left tire. The tire is in good condition, just rotated and balanced. Could I have a brake problem? Or maybe just a wheel bearing hub going out. Thanks for any help.

ok, I know this is a chevy forum, but the GMC forum aint too active. I own a 99 GMC Sierra EXCab, 5.3L. I have recently gotton my brakes worked on, rear drums replaced, new rotors, new pads in front. I have noticed a knocking sound coming from my front left tire. The tire is in good condition, just rotated and balanced. Could I have a brake problem? Or maybe just a wheel bearing hub going out. Thanks for any help.
I woild say wheel bearing, but does it only do it when you stop or what?

you don't think it could be the steering shaft, do ya? FYI, IMO 99-up GMC guys are welcome over here

Loose wheel bearing.

no, it stops doing it when i apply the brakes quickly, and it only does it really at higher speeds like 45mph-80mph, and not when i accelerate. I hope it is the wheel bearing, i know those arent too expensive, thanks for all the input.

my buddy had the same problem with his 99 gmc, if i remember rightly it had something to do with the steering linkage. sorry i can't be more accurate. it was like 4 yrs ago when he had the problem.

uhhh , not expensive for the wheel bearings ? Try approx $300 per side, the bearings are not serviceable and the entire hub assembly needs replacing unforutnately.

return it to the shop who did the work immediately

I had a 98 that was making a noise like that. Ended up that the upper A arm had a loose mounting bolt, so that when brakes were applied the A arm would move and make a noise.

I had a 98 that was making a noise like that. Ended up that the upper A arm had a loose mounting bolt, so that when brakes were applied the A arm would move and make a noise.

yup, hence my recommendation to take it back to the shop; they reassembled something incorrectly... make them recheck their work!