Sounds like warped rotors to me... tho with my rotors I could feel it at
lower speed, but I got that terrifying shudder at higher speeds (140kph...
then having to slow down.... well I didn't drive 140 anymore until I got new
brakes)

I bought cross drilled rotors as well, as when I drive on the highway I am
usually on long trips with a lot of weight in the car... and I always seem
to be in traffic at some point, so I was getting sick of brake fade... My
commuting is mostly in the suburbs, along the main industrial/commercial
roads.... Lots of fast moving traffic, and frequent stops... Again, brake
fade, the cross drilles brakes have made a nice difference! I bought
Zimmerman rotors (don't know if they make anything for Volvo, this was on my
Volkswagen) with PBR pads (there was a picture of an 850 (debadged, of
course... but you could tell) on the box.

Insurance reasons for not being allowed into the shop???... Never heard this
one before, I always go in. And talk about torque wrenches with the guy
working on the car (ie - so what do you usually torque the bolts to on this
kind of car, in case I have to do it.... they get the hint ;-) ).

On our 960 the wheel torque is stamped on the front hubs... I forget the
exact value. I would imagine it might be in the same location on your 850.
Volvo's have a pretty low wheel torque... My friends are used to working on
VW's... around 80-90 lb-ft for the wheels... Volvo's are a lot less, they
thought I was joking when I told them what I torque the wheels to.

The torque should be on the hub or dust cover. On my '93 960 it is 65
ft/lbs. That is one of (if not THE) lowest value I have seen on any
car I have owned. In comparison, the full-size Blazer I have it 95
ft/lbs as I remember.  If they used an impact wrench to tighten the
lug nuts then you have a good case for suing them for the replacement
rotors.

WHen I brought my used 960 home Ipulled all the wheels and went
through the brakes (clean and lube). The wheels were ALL overtorqued,
and one of the front rotors is slightly warped. Most folks ould be
able to tell but I can feel it. The previous owner bought tires at one
of the 'Marts.'

I too am going to replace the front rotors when they need new pads as
they have already been deeply turned (I refuse to have rotors turned
unless critically necessary).

from Randy & Valerie
    __    __
    \ \  / /
     \ \/ /
      \__/olvo
    1993 960

Torque for my 1996 Turbo sedan, 5 bolt factory alloy wheels is specified by
Volvo at:  81 ft-lb.

.... Larry