Brakes: 70: Squealing brakes - can't fix this one....

[Foeux]

Bought t5 v70. Good service history. Fresh discs, fresh pads etc. Squealing like stuck pigs.

Took the calipers apart, cleaned off all copper slip (loads) chamfered leading edge lightly, cleaned off sliders and greased, cleared and cleaned the tracks for the 'ears' of the pads to slide along. Brake cleaner on everything, very carefully back together. Everything tight, no rattle or play. Essentially new discs and pads.

Still squeals horrendously; worse than track pads. Great breaking power and feel. Pistons move freely etc. But am stumped as I have never heard squeal like it.

302mm brakes BTW.

What next? New pads and discs seems such a waste.......

[EMM]

Mine used to do it and drove me mad, mine turned out to be the anti rattle clips. However from some good advice on here,

Are the anti rattle clips in good order?
Have the pads been bedded in correctly?
Are they a good quality pad? And correct? (I say that because I have used cheap pads before and wish I hadn’t bothered).
Copper Greased? I still copper grease my pads even though I’m told I don’t need to.
When you refitted the pads did you scuff them back up? (If glazed then they won’t re bed correctly).

Andy

[Volvo V70 diesel]

Hy, Foeux,

I would lift the car from the front 2 sides, unscrew wheels off, turn hubs by hand ask someone to action the brake slowly. Do bearings noisy ?

Are you sure of the brakes cylinders, how does look the inside of each cylinder ? Seals ok ? No trace of rust anywhere ?


V70

[Clan]

Originally Posted by Foeux

Bought t5 v70. Good service history. Fresh discs, fresh pads etc. Squealing like stuck pigs.

Took the calipers apart, cleaned off all copper slip (loads) chamfered leading edge lightly, cleaned off sliders and greased, cleared and cleaned the tracks for the 'ears' of the pads to slide along. Brake cleaner on everything, very carefully back together. Everything tight, no rattle or play. Essentially new discs and pads.

Still squeals horrendously; worse than track pads. Great breaking power and feel. Pistons move freely etc. But am stumped as I have never heard squeal like it.

302mm brakes BTW.

What next? New pads and discs seems such a waste.......

I would just fit the correct volvo parts , job done ...

[Foeux]

Originally Posted by EMM

Mine used to do it and drove me mad, mine turned out to be the anti rattle clips. However from some good advice on here,

Are the anti rattle clips in good order?
Have the pads been bedded in correctly?
Are they a good quality pad? And correct? (I say that because I have used cheap pads before and wish I hadn’t bothered).
Copper Greased? I still copper grease my pads even though I’m told I don’t need to.
When you refitted the pads did you scuff them back up? (If glazed then they won’t re bed correctly).

Andy

Any rattle shims were not in great order so binned. Never had volvo pads with them before. Not sure of pad manufacturers. Had ec90 stamp visible so not illegal. Didn't scuff them, didn't know what trick but they didn't look glazed. Greased sliders and the tracks but not pad backs. No idea who bedded the pads in or how. Have had conflicting advice on how it's done.

Originally Posted by Volvo V70 diesel

Hy, Foeux,

I would lift the car from the front 2 sides, unscrew wheels off, turn hubs by hand ask someone to action the brake slowly. Do bearings noisy ?

Are you sure of the brakes cylinders, how does look the inside of each cylinder ? Seals ok ? No trace of rust anywhere ?


V70

Checked for bearing play - none. Pistons pushed back easily with thumbs and the seals were dry, supple and unbroken. No rust, plenty of brake dust everywhere.

Originally Posted by Clan

I would just fit the correct volvo parts , job done ...

Can you tell me. If volvo fitted anti squeal shims?

[Volvo V70 diesel]

Originally Posted by Foeux

Bought t5 v70.
...302mm brakes BTW.

Sorry to ask such a question, but yours pads are fitted for the 302 mm ? Did you change also the calipers ?

VV 70

[Clan]

Originally Posted by Foeux

Any rattle shims were not in great order so binned. Never had volvo pads with them before. Not sure of pad manufacturers. Had ec90 stamp visible so not illegal. Didn't scuff them, didn't know what trick but they didn't look glazed. Greased sliders and the tracks but not pad backs. No idea who bedded the pads in or how. Have had conflicting advice on how it's done.



Checked for bearing play - none. Pistons pushed back easily with thumbs and the seals were dry, supple and unbroken. No rust, plenty of brake dust everywhere.




Can you tell me. If volvo fitted anti squeal shims?

No they don't need them , they engineered the discs and calipers and pads together to be quiet and they are .... I remember back in around 1978 when asbestos was withdrawn from pads there was a squeal problem on the rear discs and they did issue thin stainless steel shims . But today they use the cast iron lumps on the calipers , they have different weight ones for different discs and pads to tune out the noises .

[EMM]

As already mention fit a good quality set of pad and reinstall the Anti rattle clips.

The anti rattle stops the pad rattling in the calliper and thus stops most if not all the squeals (Please don’t shoot me as I’m only going on my experience). For the cost of a full set of anti rattle clips for the front and rears it’s one less thing to worry about.

Then I would put another set of OEM front and rear pads on.

I run Porsche front and S60R rears calipers and I used a Mintex pad instead of my normal textar pad. Squealed so loud that you knew I was coming, my wife would know when I had picked her up at work because she could here me - she works in a hotel, ha. Changed to the textar (also made by Mintex) and it had a 1mm difference.. Squeal gone after bedding in.

[Simmy]

Originally Posted by Foeux

Bought t5 v70. Good service history. Fresh discs, fresh pads etc. Squealing like stuck pigs.

Took the calipers apart, cleaned off all copper slip (loads) chamfered leading edge lightly, cleaned off sliders and greased, cleared and cleaned the tracks for the 'ears' of the pads to slide along. Brake cleaner on everything, very carefully back together. Everything tight, no rattle or play. Essentially new discs and pads.

Still squeals horrendously; worse than track pads. Great breaking power and feel. Pistons move freely etc. But am stumped as I have never heard squeal like it.

302mm brakes BTW.

What next? New pads and discs seems such a waste.......

brembo pads have anti squeal shims bonded to the rear of them .always quiet

[canis]

Here's some more conflicting advice for you:

I clean the discs thoroughly with meths. Some people say you don't need to, I disagree.

I don't use copper ease. Some people say you need it, I manage without. It's tempting to imagine the brake pads moving, like on a bicycle. In reality they don't do this. In reality they move barely at all, microscopically in fact. The sheer hydraulic pressure involved requires no lubrication. It is therefore my opinion that adding lubrication to calipers will increase squeal and judder. In any case, I've never used it, and my brakes don't squeek.

Those little springs on the pads - make no difference. Sometimes I've had them, sometimes not. Either way, mine don't squeek.

Bedding in - big contentious issue this. I've not experience this mythical "spongy" brakes during bedding in. Without doubt, the pads and discs will score, and of course they will match each other after a time, but this idea that brakes are poor when brand new and for the next hundred miles is simply false. If they're spongy, it's due to poor bleeding, and careless fitment.

I use bog-standard brakes. Currently Unipart. Cheapest I can find. And they work perfectly, easilly within legal limits and I have absolute confidence in them. When I step on the pedal, the car stops.

All things considered, my experience (over thirty years) has been that most brake issues are caused by failing to pay meticulous attention to cleanliness, a lot of excuses, many myths and lashings of copper stuff.