[M33DLO]

Hi guys.

I've been fighting with a high pitched brake squeal on my 340i for years.
My first issue was when pulling away slowly after the car had been sitting for a while, the front brakes would squeak until about 10-15mph, then be silent.
Very annoying.

I was due a front brake refresh (discs and pads) so just lived with it.

Fitted new 2 part discs and matching pads:

https://www.autodoc.co.uk/brembo/8138899
https://www.autodoc.co.uk/brembo/8714344

They were fine for about 250miles but now they squeak when slowing from around 10-15mph until stopped.

I fixed the pulling away squeak, but replaced it with an even more annoying stopping squeak.

Last weekend I pulled the pads and applied Mintex CeraTec lubricant to the backside of the pads, also along the edges where they slide inside the caliper, also the retaining pins.

No positive result.

Any ideas?
More lubricant?
Try a different pad?

[danb1979]

I've never been a fan of Brembo pads (squeaky, overly dusty and they always seemed to have a 'soft' feeling to them to me)

Have you tried to bed them again to see how they get on after that?

I run dimpled / grooved discs all round with OEM BMW pads and zero issues. Quiet with no noise/squeaks etc...

They can squeal after I've washed the car and then it's been sat. But as soon as I brake and the faces clear they're silent again.

I'd say deffo try different pads and see how you get on with them. But after you've tried to bed the current ones in again.

[NanasBack]

Are they the blue caliper brakes?

Mine did it from new at low speed, when stopping - a real pain.
Probably for 12 months or more.

It generally goes away when it's wet or damp.

Strangely, it's just started again, within the last few days.

Try bedding in procedure again.

Fiik what causes it.

[SimonBMW1]

Get oem m4 pads. Good upgrade

[danb1979]

Originally Posted by SimonBMW1

Get oem m4 pads. Good upgrade

Do hey fit the Brembo calipers for 340mm discs; I know they fit the 370/345mm calipers (they're on my upgrade list)?

[SimonBMW1]

Originally Posted by danb1979

Do hey fit the Brembo calipers for 340mm discs; I know they fit the 370/345mm calipers (they're on my upgrade list)?

I thought all 340 and 440 had 370mm. Hence i mentioned. No idea if they will fit

[danb1979]

Originally Posted by SimonBMW1

I thought all 340 and 440 had 370mm. Hence i mentioned. No idea if they will fit

So did I!

OP - you sure your brakes aren't the 370/345mm Brembo set up?

[M33DLO]

My 340i is an early one, with the grey 4pot Brembo callipers. 340mm disc.
(yes, I have a slight blue calliper envy problem, ha)

[TurboWeasel]

I had the same problem with ATE discs and pads from AutoDoc, and also warpage!

Switched to BMW discs and pads and they have been absolutely silent for many 1000s of miles so far.

As is common with aftermarket pads, they supply 4 identical pads, whereas the genuine ones have different backing plates on the outboard ones. It does make a difference.

Make sure to use ceramic brake grease on said plates and all sliding surfaces the pads ride in, and also thoroughly clean said sliding surfaces of old baked on brake dust, and you will stand the best chance of a squeal free life.

[danb1979]

Originally Posted by TurboWeasel

I had the same problem with ATE discs and pads from AutoDoc, and also warpage!

Switched to BMW discs and pads and they have been absolutely silent for many 1000s of miles so far.

As is common with aftermarket pads, they supply 4 identical pads, whereas the genuine ones have different backing plates on the outboard ones. It does make a difference.

Make sure to use ceramic brake grease on said plates and all sliding surfaces the pads ride in, and also thoroughly clean said sliding surfaces of old baked on brake dust, and you will stand the best chance of a squeal free life.

Think you were unlucky with your ATE discs & pads

My pal Chris has just got his from Autodoc and very clearly labelled inside/outside and with the necessary anti-squeal backs on them etc

They are the ceramic pads though he's got with ATE blank discs

But agree with the cleaning of the brakes - so many folk skip this part and just whack on the new brakes and that's it and the wonder why they have issues afterwards...

That and 30 bejillion globs of copper grease everywhere too

[Alscoob]

I've had standard BMW 370mm discs and BMW grooved and dimpled discs with BMW pads and with other pads, they have all squealed at some point at low speed in both my 330d and 340i F31's

Have used Brembo HP2000 pads with BMW plain 2 piece discs, no squeal and a good upgrade.

For info by others......

https://f30.bimmerpost.com/forums/sh....php?t=1952879

[Samuaw]

I echo the bedding in procedure as mentioned before.
Braking till you can smell the brakes (with the correct procedure of course) did the trick on my notoriously squeaky ds2500.

Though I would say when I did it, I didn’t do the full procedure and the squeak did some back a few months later but after an outing on track- it has never come back since. So enhanced bedding in is still my recommendation

[Eddamoo]

Did you clean the slider pins and properly check the pads had completely free movement before fitting the shim and pins? If they're making noise up to 15mph that indicates they're binding a lot.

I ask as our X4 with Jurid pads started squeaking and sticking. The problem was slight skimming m aluminium oxide corrosion where the pad slides into the caliper. It needed a good rub down and I also had to take the anti squeal coating off the edges of the pads to allow free movement.

Ever since then they haven't made a peep.

[M33DLO]

Originally Posted by Eddamoo

Did you clean the slider pins and properly check the pads had completely free movement before fitting the shim and pins? If they're making noise up to 15mph that indicates they're binding a lot.

I ask as our X4 with Jurid pads started squeaking and sticking. The problem was slight skimming m aluminium oxide corrosion where the pad slides into the caliper. It needed a good rub down and I also had to take the anti squeal coating off the edges of the pads to allow free movement.

Ever since then they haven't made a peep.

Yes I wire brushed and wiped down the pins and ensured I had free movement along the slide guides inside the calliper.

My Brembo pads have 2 anti squeak plates it seems, a black one that curls around the edges of the pad, and then a flimsy chrome plated one.
Maybe I will try removing the flimsy one and applying some more grease after a clean.

[TurboWeasel]

Replace the slider pins, don't clean them. They suffer from micro abrasion and can bind as Eddamoo mentioned.

What I do is check the pads slide easily and cleanly before final assembly. If not, I finesse the pads with mini files accordingly. But not too much on the sides as you can get pad knock if you shave them down too much. The BMW pads have a special 'spongy' material that wraps around the sides of the pad to prevent knocking. Do the Brembos have that as well?

[M33DLO]

Originally Posted by TurboWeasel

Replace the slider pins, don't clean them. They suffer from micro abrasion and can bind as Eddamoo mentioned.

What I do is check the pads slide easily and cleanly before final assembly. If not, I finesse the pads with mini files accordingly. But not too much on the sides as you can get pad knock if you shave them down too much. The BMW pads have a special 'spongy' material that wraps around the sides of the pad to prevent knocking. Do the Brembos have that as well?

Would the binding correspond to why they would squeak while pulling away.?
My issues are when coming to a stop.

The pads move freely within the slide grooves.
I didnt notice anyhthing spongy on the sides of the Brembo pads.

[TurboWeasel]

Originally Posted by M33DLO

Would the binding correspond to why they would squeak while pulling away.?
My issues are when coming to a stop.

The pads move freely within the slide grooves.
I didnt notice anyhthing spongy on the sides of the Brembo pads.

I guess so as the pads would need to be in contact with the disc to squeak, so they could be sticking.

The main issue with the blue brakes is squealing when coming to a stop at slow speeds as you mentioned. I don't think mine ever squeaked when pulling away from a standstill though. That's a bit odd.

In your situation I would check everything over again and sling some BMW pads in, but it's time and money I guess.

[M33DLO]

OK, progress..
I got in there again and removed the flimsy chrome plate from the Brembo pads.

NO SQUEAK! SILENCE!

I'll give it another test in the morning and report back.

[M33DLO]

Yeah, fixed.!

Lets see for how long.

[MY340i]

nice one - glad its sorted.

[M33DLO]

Nahhhh... It's returned. FFS.
Very odd how it develops after a 100miles or so.

I think a change of pads is in order.
What are we recommending? I dont need anything high performance as the 340i is our family duty daily basher.

[danb1979]

OEM BMW pads.. Don't faff about. Fit them and forget all about it.. I've been really impressed with them partnered with the M Performance discs on my F31 and glad I stuck with them & not aftermarket etc