When you do pads and rotors, please clean and grease the caliper guide pins. If the calipers can’t “float” and follow any lateral runout, the pads will wear down the local high spots during off-brake operation, which creates variation in disc thickness which manifests itself as brake torque variation aka pulsation that will cause Hella steering shake when braking.
AngryCorvair said:When you do pads and rotors, please clean and grease the caliper guide pins. If the calipers can’t “float” and follow any lateral runout, the pads will wear down the local high spots during off-brake operation, which creates variation in disc thickness which manifests itself as brake torque variation aka pulsation that will cause Hella steering shake when braking.
I've done a few of these GM floating caliper deals. We have a setup of them on the rear of the Plymford. I _always_ _always__always_ grease the pins. And put a very light skim coat on the back of the pads.
Update- last night around a quarter to 9, I took the 'Burb out for a bedding session. 8 runs were made, all starting at between 50 and 55 mph, braking hard down to just a rolling speed, then accelerating back to 50-55 and braking again. After the last braking run, still without fully stopping, I cruised around slowly for about 15 minutes WITHOUT touching the brakes at all (back country roads at night) before pulling into the driveway. I used the parking brake to fully stop, and then let the truck sit for an hour.
About 10PM I went out for a test drive, and the situation was significantly improved. There were still some detectable pulsations, but at medium and light braking (I didn't do any hard stops this time) it was noticeably less than it had been.
I think what I will do now is get some good pads, swap them out, make another bedding session, and hopefully the situation will be pretty well resolved.
Thanks again for all the input, fellows! Happy Friday. 
Getting a different type of pad and trying to bed it to the same rotor can make this situation worse... just fyi.
wvumtnbkr said:Getting a different type of pad and trying to bed it to the same rotor can make this situation worse... just fyi.
On typical passenger car I would agree with you. But on a 2500-series Suburban, front pads should be semi-met and will probably clean up OK. Semi-Mets don’t rely on transfer layer as much as organics and ceramics do.
In reply to AngryCorvair :
Thanks for the info!
In reply to AngryCorvair :
Most of the options for the 'Burb are semi-mets, which is what I'd planned on going with. I installed a set of Raybestos semi-mets on Mrs. VCH's old Suburban ('91) on the original rotors, and they've worked well.
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