Brake Shake....

[Diver88]

Hi, just joined because I'm looking for answers.. I have a 1996 C-1500 regular cab, long bed, bought it brand new and for the first 90K miles it had fantastic overall braking,
no complaints or issues. I had the rotors turned and pads installed by a shop, 3K and the front end is bouncing up and down coming to a stop. When it needed new pads I asked the shop
to replace the rotors and pads, a few thousand miles and the same situation occurred. I have 227K miles on her and not counting the original brakes the rotors and pads have been replaced
6 times and I still have the same problem. I'm getting even pad wear side to side and it stops well but the front end bounces up and down very noticeably still today. It was suggested I didn't "bed"
the pads in, which I have never done on any vehicle including this one and I have never had this problem on any other vehicle I have driven or owned. So, I tried overheating the brakes stopping
from a high speed several times in a row and, no more bouncing coming to a stop..... until I drove around another hour and the bouncing came back. My current mechanic say none of this makes sense
and he say's the "bedding" of new pads is nonsense. I've taken care of this vehicle meticulously although age is catching up and a few things need to be done
but I'd really like to solve this brake problem, any suggestions would be greatly appreciated.

 

[RichLo]

Have you had the rear drums off at all to inspect their condition?

 

[Caman96]

I noticed you said “rotors and pads”, but no mention of calipers being replaced. Have they been checked or serviced? To RichLo’s point, you could try just stepping on parking brake to isolate rear brakes. Many new parts suk too, what parts are you using?

 

[Orpedcrow]

Does the shake happen in the steering wheel? Or mostly in the seat/floor? ABS light on when it happens?

Stock suspension and tires? Towing heavy often?

Could be my comprehension skills but are you saying the shaking happens under braking regardless of how new the brakes are or only after a few thousand miles? So it still shakes when pads and rotors are new?

I wouldn’t say bedding is nonsense, it does serve a purpose.

As @Caman96 questioned, what parts are you using? A lot of new brake rotors are garbage that warp easily because they are made from inferior materials and there is t as much material in them to properly dissipate heat.

 

[Carlaisle]

Is the front end "bouncing up and down" when you apply the brakes or is it vibrating? I suspect the latter, which is a common symptom of warped rotors. All of the new rotors I have acquired made from Chinesium did this to some degree, and very quickly after installation. I considered machining some from solid steel but don't have a lathe with sufficient swing to pull it off.

 

[FullBlowncustoms]

With EVERYTHING being correct? Only time I have seen that is if the E-brake was partially on.. At a stand still on flat level road, let foot off the brake at just idle, see if it starts to roll forward or starts to lump, or not roll move at all.

 

[FullBlowncustoms]

Oh also... On my 95 K1500 at the older Hayes pump ABS thing I had to bleed a rubber nipple thing on side of it. Was MANY years ago so I don't remember it. Someone on here would know.. Just extra info for you is all.

 

[Schurkey]

1. Multiple sets of pads, multiple sets of rotors, same problem. I was thinking that It's probably not the front brakes, until you mentioned that using the brakes "hard" fixed the problem temporarily. Are you one of those drivers that brakes gently for a block-and-a-half before each stop sign? That's poor practice.

2. Might be the rear brakes. Test with park brake as described previously. Pray that the park brake cables aren't seized.

3. Bounces up and down? How old are the shock absorbers?

4. How old are the tie rod ends, ball joints, control arm bushings, idler arm, Pitman arm...is braking force moving the worn-out suspension/steering parts in a way that affects wheel alignment?

 

[Erik the Awful]

My current mechanic say none of this makes sense and he say's the "bedding" of new pads is nonsense.

A lot of the time you can get away without bedding pads, but you've found an exception. My bedding process isn't extreme, but I do it with every brake job. I drive through the neighborhood to the main road, doing some moderate braking to warm the brakes up a bit. I get up to speed on the main road and jam on the brakes once firmly for the slow-down to turn back into the other entrance to the neighborhood. I then drive back to the house using moderate braking. That's a minimalist bedding.

I'd take your brakes back apart. Get a brown roloc pad and scuff both rotors front and back to remove brake material embedded in the rotor. Replace your pads, because the old ones are glazed and new quality pads are cheap. https://www.rockauto.com/en/moreinfo.php?pk=298290&cc=1031500&pt=1684&jsn=975

Clean the brakes and pads with brake cleaner. Reinstall and use a thorough bedding procedure. As Schurkey said, don't ride your brakes.

 

[Supercharged111]

I had a problem on track with a particular pad once. No matter the bedding process it always came back. The pads would just leave deposits no matter what. I'd used a rotor home between events and that would make it go away, but by the 2nd session it was back every time. If your problem is pad deposits, and you've tried the same pad 6 times I could see that being an issue. Lots of people use the pad I had trouble with and get along just fine. There's just something about that pad me and the car aren't compatible with.