Shaking when Braking - 07 Malibu LS
 

Hi All,

I'm new here and am hoping someone has figured out a problem several of us Malibu owners have.

I have a 2007 Malibu LS (2.2 Engine) and have been experiencing very noticeable shaking on my front driver-side wheel. It would squeak when braking at low speeds (25MPH or less) but shake heavily when braking at faster speeds (above 40MPH). I figured it was a warped rotor and worn pads, so I replaced them this morning. BTW, the pads (organic) were still in pretty good shape and the rotors weren't warped or grooved.

The squeaking is gone (ceramic pads), but the shaking has become even more noticeable. It literally rattles my dashboard when breaking but immediately goes away when the car reaches 20MPH or below. The shaking is consistent and doesn't slowdown as the vehicle slows down. It's almost like having an antilock braking system (which I don't have) and I wasn't braking hard.

Each article I can find always says that it's a warped rotor or a balance issue. I haven't had anything to support that. Like I said, I just replaced the rotors and pads this morning and it's even more noticeable. The tires are brand new and have been spun balanced and an alignment was done during the installation of the new tires.

I've checked to see if the transmission mounts or engine mounts were cracked (which they weren't) and haven't seen any unusual wear or tear on any structural part of the car. I checked to see if there was any side-to-side play in the tires and it's all good.

if the shake occurs only when braking it is most likely brake related. tires would shake all the time.


does the shake transfer through the steering wheel or brake pedal?

I feel a pulsing in the brake pedal and the steering column trembles (meaning more up and down than a pulling left and right). I hear no external noise, the only noise is a loud vibration in the dashboard (kinda like the rumbler when a plane flies too low). All of it stops when the car reaches 20MPH or below.

I assumed it was a rotor or pad issue and that's why I replaced the rotors and pads in the front. I'm wondering if it's the rear brakes, but am confused on why that would cause the trembling in the steering column.

I know others have complained about the same thing, but everyone says it's a warped rotor. I know it's not the case in this situation (the front rotors, that is). I'm also wondering if it's that same as this service bulletin, even though it's not for this model car.

Bulletin No.: 07-05-23-003B
Date: April 28, 2009
Subject: Pulsation/Vibration When Applying Brakes (Repair Rotor Variation and Install New Front Brake Shields)
Models:
2005-2007 Buick Terraza
2005-2009 Chevrolet Uplander
2005-2009 Pontiac Montana SV6
2005-2007 Saturn Relay Supercede:This bulletin is being revised to add the 2009 model year and update the labor operations. Please discard Corporate Bulletin Number 07-05-23-003A (Section 05 - Brakes). Condition
Some customers may comment on a pulsation/vibration felt when applying the brakes.
Cause
This condition may be caused by the brake pads and rotors wearing unevenly due to debris.
Correction
Repair the rotor variation and install new front brake shields using the steps below:
1. Verify that the condition is from the front brakes.
2. Correct the rotor variation by referring to the Brake Warranty Service and Procedures Bulletin Number 00-05-22-002 or later. Important
Measure Lateral Run Out (LRO), brake rotor thickness specification and document the information on the repair order. Include the warranty claim code and ONLY claim this Special Labor Operation H9725* for this bulletin.
3. Remove the front wheel bearing/hub. Refer to Front Wheel Bearing and Hub Replacement in SI.
4. Remove and discard the old front wheel speed sensor bracket and old wheel bearing/hub bolts.
5. Install the new front brake shield (1). Important
The wheel bearing/hub bolts must be replaced.
6. Install the front wheel bearing/hub. Refer to Front Wheel Bearing and Hub Replacement in SI.
7. Repeat this entire procedure on the opposite side.
8. Verify that the condition has been corrected.
19167950: Shield Front Brake LH
19167253: Shield Front Brake RH

if you feel it in the brake pedal, its from the rear. do you have diisc or durm brakes in the rear? change the back and see where your at. There could be other factors but address the rear first.


the tsb shouldn't apply. it is possible that you have stacked tolerances causing runout but that is rare. did you check for loose wheel bearings? Did you clean the hub mounting surfaces? its also possible that the new rotors are not true. I would address the back brakes first before doing anything else.


Putting new parts on is only one step in servicing brakes. Everything must be cleaned and lubricated so the floating caliper and pads can apply and release properly.

Yeah, the rear brakes are pretty much where I'm leaning to right now. They're disc brakes, so the replacement shouldn't be too difficult.

As for the cleaning the front, I prepped the rotors with brake clean, steal brush the posts and threads, greased all the areas where the pads would slide, and used CRC heavy silicone on the slide pins so the rubber doesn't wear out.

Thanks for your input. I'll update you on what happens later.

*** UPDATE ***
The back brakes are actually drum brakes. I'm taking it in now to have that serviced because I'm not that familiar with drum brakes and don't trust my skill set. It seems a little more involved when it comes to the emergency brake.

I haven't done rear drums on anything after 2002.

They really aren't bad. You just need the pads - a spring kit to rebuild with, and a spring remover tool.. It's like a big scissor that pulls the springs so you can slide it onto the mounting posts.

You may or may not need another spring type tool to do the other springs (sometimes it's integrated into the same tool).

Just take some good pictures with your phone and note where everything is located. This spring behind those, the lever in the middle... orientation.

When taking everything off - lay it out on the ground exactly like it was.

Do not do the other side until the other side is complete (so you have something for comparison if you screw it up).

Also a hayne's manual will go a long way with step by step instructions.

There are some youtubes available. Check them out.

Here is the tool with the combo (pliers, and the thing on the back end of the one handle).

http://www.autozone.com/test-scan-an...ers/46854_0_0/

his drum spring is different. Its requires different tools as it looks like this


http://www.lislecorp.com/uploads/pro...5479AE49BB.jpg

Thanks for the update. I saw those tools online when I searched and was like WTF is that for. I'm too old school, but not that old school that I've worked on a car with a carb.

Thanks tech2 and sledge.impy. I just took it in. Next time I'll do it myself. I'll probably do it twice as fast and 3x cheaper. :)

Either way, it wasn't the back brakes either (the shoes and drum did need replacing). They called some service techs and all said the same thing, front rotors and hot spots. What they are saying is even if the rotors are brand new, they still will need to be machined down to spec.

It sounds plausible, but without anyone to confirm this, it's suspect. I don't feel like shooting money at something without some data from the field to back it up. They also brought up that they are getting in a lot of Malibus, even current models due to calipers.