- 01/03/2015
- 1 Min Read
- By: Alex Fiehl
Your Volvo's Vibrating Rear Brakes Are Probably Fine
There it is. I'm test driving a used Volvo, and it happens. Every.Single.Time. I ease into the brakes, exclaim expletives, and finish the test drive in my usual peeved attitude. Smooth brakes are something I'm very picky about. At 120mph it feels great to stomp on the brake pedal and lock the seatbelt feeling nothing more than extreme g-forces, hearing the tires grumble and moan on the tarmac. When the steering wheel vibrates and the body chatters, I get angry.
Every car I've ever test driven has had warped or pulsating brakes. I don't think I've ever brought a car home without immediately ordering rotors the next day. This is the story of my '96 850.
Volvo OEM Brake Pad w/Full Backing Plate
It still vibrated
After throwing a new set of rotors and Akebono Euro Ceramic pads on the back of my Volvo 850 Platinum I thought I'd be all set. Much to my chagrin, it still vibrated like crazy on the highway under moderate braking. The car had over 180,000 miles, but had thousands of dollars in work done recently. It was the epitome of "Stage 0."
I was stumped because nothing had failed, and nothing appeared wrong with the brakes, steering, or suspension. Even the Nivomat shocks and large front 302mm rotors were brand new. The vibration was horrible; I was not a happy guy. It felt like driving on grooved pavement when I hit the brakes, and the interior clattered every time to remind me.
Volvo engineered special shims
Given an afternoon of searching, I discovered that Volvo was aware of this problem too. It's all in the shims. Created for the '93-00 FWD P80 platform vehicles, these are Volvo's clever way of killing a nasty vibration without redesigning the more expensive braking components.
Volvo Half-Shims for 850/S70/C70/V70
The Genuine Volvo shims (272272OE) replace whatever backing plates/shims are currently installed on the rear brake pads. By only allowing the caliper's pistons to apply force to one half of the brake pad, they prevent a horrific resonance from cropping up in the rear end and smooth deceleration is restored.
When installing, ensure that the arrow is pointing in the direction the wheel rotates when traveling forward. I coated both sides in a little silicone brake lubricant as well to stick the shim to the pad and make sure they never squeak. Problem solved. Just make sure you remember they're installed next time you or a shop does a brake job, you don't want a set of $20 shims to get scrapped if they're still in good shape.
Strangely, it seems that some vehicles are more sensitive to this resonance than others. One Volvo 850 in our family can run any brake pad available with no vibration, while my father in law's 850 will vibrate unless it has these shims installed. They look strange, but they work, and are worth a shot if your FWD Volvo has a strange shudder in the back.
About the Author: Alex Fiehl
Alex
is FCP's Blog Editor and a Desktop Engineer from Endwell, NY. He has over 9 years of experience working on a wide array of import makes, but has found his home with European cars. With a Volkswagen and Volvo at home, the garage is always busy.
