850 "Clunk" noise on braking?

[Jim Martin]

Hello Volvo Guys:

Our 850 makes a clunking noise when you brake. I believe it is associated
with the rate of declaration. That is, if you brake gently you may not get
it till you come to a stop but if you brake hard you will hear it
immediately. My sense is that something is shifting under the deceleration.
Is this a common thing? Anyone care to enlighten me? Motor mount?

As far as I know the steering and suspension are all in good shape and the
joints are all tight. The car drives and handles nicely. Nothing was obvious
to my local mechanics but he is not a Volvo suspension expert.

Thanks in advance,

Jim

 

[Joe landy]

My V70 had a similar clunk about a year ago. It also showed up when
Accelerating hard.
Turned out to be the top engine mount, right on the back of the engine.
Mine's a diesel, and the mount is behind the engine, where the turbo fits.
It ties the engine to the bulkhead. More of a support/steady than an engine
mount. The part which needed replacing was a bush, and I made a tool for
pressing the old one out, and pulling the new one in, without having to
remove the turbo, which is sort of in the way.
If your clunk sound proves to be this mounting worn, I can give you a
drawing of the tool I used to replace the bush.
If you're in the UK, I could post you the tool so you can use it.

If it isn't this bush, check brake calipers for movement. Hopefully the
mounting bolts won't be loose.
Also, check the pads aren't floating around in the caliper. I once fitted
some after market pads, and they didn't have the correct shape of 'ears' on
them, and they managed to rotate in the caliper.

If nothing on the braking, or suspension setup looks suspect, check for
objects floating around in the boot/trunk. A wheelbrace which wasn't tied
down gave me loads of stress once!
p.s remove NO.SPAM to reply.

All the best.
Joe Landy.
Peterborough
UK.