S70 brake squeal

  • Thread starter Thread starter Armchair observer
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A

Armchair observer

After having front and rear brake pads replaced on my S70 at 100K
(rotors resurfaced) at a local garage, there is a pronounced squeal
when braking at low speed. Is this because the garage failed to use
special grease on the pads? Can the squeal be silenced by reinstalling
the pads with the proper lubricant?
 
Armchair observer said:
After having front and rear brake pads replaced on my S70 at 100K
(rotors resurfaced) at a local garage, there is a pronounced squeal
when braking at low speed. Is this because the garage failed to use
special grease on the pads? Can the squeal be silenced by reinstalling
the pads with the proper lubricant?
Click to expand...

If they didn't use Volvo pads, you probably won't be able to get rid of
the squeal. The grease goes between the back of the pads and the wheel
cylinders and is not a lubricant but a dampening agent. It functions
like a shock absorber and tries to disipate resonant vibrations. If the
pads are Volvo pads matched to Volvo discs, then the grease should work.
 
Good morning all.
The Genuine pads I use on my V70 have a rubber coating on the back,
replacing the need for grease. If you can't see any grease on the pads but
they are genuine parts, you (probably) have no reason to change them.
I agree with Mr Henning in that Pads MUST be the same make as the discs. The
materials are carefully matched to each other to prevent squeal.
I have used pattern discs on the rear, with matching pattern pads, and I
have no squeals!
There are also a couple of anti-squeal springs on my V70, and it's worth
changing them when you do the pads. They don't last long.

Cheers.
Joe landy.
Peterborough
UK.
1997 V70 TDI 250,000 miles.
 
Stephen M. Henning said:
If they didn't use Volvo pads, you probably won't be able to get rid of
the squeal. The grease goes between the back of the pads and the wheel
cylinders and is not a lubricant but a dampening agent. It functions
like a shock absorber and tries to disipate resonant vibrations. If the
pads are Volvo pads matched to Volvo discs, then the grease should work.
Click to expand...

I have non Volvo pads (Textar, a Volvo supplier) and discs (Zimmerman)
on the rear of both my S70 and V70. The V70 for about a year and a half
(30,000 km) the S70 for only a couple of months. No squeals or any
other noise. However, there are some pads that are available that will
squeal no matter what you do. Part of the problem is that exact
physical dimension fits 240s,740s as well as older Mercedes and some
BMWs. So this high volume entices some of the lower quality pad makers
who make one pad that fits all, but doesn't work well in any. However
if you get proper pads from a quality manufacturer, they'll work fine.

--
Mike F.
Thornhill (near Toronto), Ont.

NOTE: new address!!
Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)
 
Mike F said:
However
if you get proper pads from a quality manufacturer, they'll work fine.
Click to expand...

No really. The pads must match the rotor. Some rotors are softer and
use softer pads. Some rotors are harder and can use harder pads. Volvo
engineers sweat bullets getting a rotor and pad match that will not
fade, is not noisy, will stop smoothly, is not toxic, will not wear too
fast, and will not squeal. It is not a trivial task. Some very
expensive pads will squeal if they are not used with the right rotor.
Volvo uses all kinds of gimmicks to prevent brake squeal such as pad
grease, rubber pads, springs, etc.

As someone else stated; it is best to buy pads that match the rotor. If
you go with non-Volvo rotors, then you need to find compatible pads.
The match-up is not trivial. If engineers could use any high quality
pads, they would use ones that created much less brake dust.
 
Stephen M. Henning said:
No really. The pads must match the rotor. Some rotors are softer and
use softer pads. Some rotors are harder and can use harder pads. Volvo
engineers sweat bullets getting a rotor and pad match that will not
fade, is not noisy, will stop smoothly, is not toxic, will not wear too
fast, and will not squeal. It is not a trivial task. Some very
expensive pads will squeal if they are not used with the right rotor.
Volvo uses all kinds of gimmicks to prevent brake squeal such as pad
grease, rubber pads, springs, etc.

As someone else stated; it is best to buy pads that match the rotor. If
you go with non-Volvo rotors, then you need to find compatible pads.
The match-up is not trivial. If engineers could use any high quality
pads, they would use ones that created much less brake dust.
Click to expand...



Well, I've been using quality pads and quality discs from a variety of
manufacturers on several types of Volvos for many years and have never
had a problem with squealing or premature wear, so I guess I'm just
lucky.

--
Mike F.
Thornhill (near Toronto), Ont.

NOTE: new address!!
Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)
 
I'm not sure Volvo engineers do sweat bullets over this. I think it will be
more of a case of Volvo engineers developing a spec (size, retardation etc)
and passing that on to a third party to develop the brakes on their
behalf.... and then selecting a solution on the basis of least cost

This is why Volvo pads are the same size/shape as those other manufacturers
use...

Like Mike, I have used various rotor/pad combinations on various cars and
not really had a problem....
 
AB said:
I'm not sure Volvo engineers do sweat bullets over this. I think it will be
more of a case of Volvo engineers developing a spec (size, retardation etc)
and passing that on to a third party to develop the brakes on their
behalf.... and then selecting a solution on the basis of least cost
Click to expand...

The reason they sweat this is because owners take their cars back many
times if the brakes squeal and complain. The only thing the shop can do
is say they got a bad batch of pads and burn money by burnishing the
rotor and replacing the pads properly. It is a very simple thing that
can cause a lot of customer relations problems. If they get it right the
first time, it is no sweat.

One reason they use such soft pads that give off tons of dust is to keep
squealing down. The other reason is they can't use asbestos. In the
good old days pads were much harder and cheap replacement pads were much
more prone to cause squealing. Now with softer pads they even use a
slightly softer metal in the rotor.
 
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