Why Do My Front Brakes Squeal?

[ReganAndCarter]

Been driving me nuts. 2004 Fiat Scudo van. Took it to local garage last October as tyre place I used couple of weeks earlier mentioned the pads and discs were worn.

Garage said discs were quite substantial so not to change them and new ones are pricey. They just changed the pads.

Anyway, it was a bit squeaky to start, but I thought it would bed in. Drove van to Poland and back, still the same. Now done approx 3500 miles on the new pads so reckon they're bedded in. They do quiten down a bit when they warm up a bit. Why are my brakes still squealing (almost like a high pitched whistle)? Has the garage missed something?

As always, appreciate any help, because they are quite noisey and it's not getting any better.

 

[Burnerman]

I agree, dust build up is the first culprit but if all else fails, a change of pad make should do the trick.
John
Allow me to edit this one.....if the disc surface is glazed - maybe due to the brakes having stuck on in the past and overheated them - then a squeal can result.
Often the surfaces have a bluish tinge due to the heat involved.
J.

 

[ReganAndCarter]

Thanks to both for your replies. Never had a problem with the brakes before, so hoping to rule out glazed discs. Will have a look, but as the noise started straight after pad change, I doubt it.

May try removing the wheels and giving discs and calipers a blast with brother's pressure washer. If still the same, get the tube of Copper Slip out.

 

[Burnerman]

If the brakes squeal all of the time then the pads are gently kissing the disc. This is either due to the pads sticking ever so slightly in the calipers, or they are not retracting when you release the brake pedal.
The pad release method is actually due to the action of the square section fluid seal in the caliper.....as it distorts under brake pressure it pulls the pad back just a fraction when you release the pressure.
If the brakes squeal when you press the brake pedal then its either dust build up or disc / pad glazing.
The back of the pads and all of the sliding surfaces benefit from a good smear of white ceramic brake grease.
Time to get out more, perhaps!
John

 

[Harry Bloomfield]

I have cured some by simply putting a saw cut part way through the middle of the pad material.

 

[ReganAndCarter]

If the brakes squeal all of the time then the pads are gently kissing the disc. This is either due to the pads sticking ever so slightly in the calipers, or they are not retracting when you release the brake pedal.
The pad release method is actually due to the action of the square section fluid seal in the caliper.....as it distorts under brake pressure it pulls the pad back just a fraction when you release the pressure.
If the brakes squeal when you press the brake pedal then its either dust build up or disc / pad glazing.
The back of the pads and all of the sliding surfaces benefit from a good smear of white ceramic brake grease.
Time to get out more, perhaps!
John

Thanks again, John. They only squeal when the pedal is pressed.

 

[Burnerman]

In which case, the calipers are just fine which is a good thing.
I suspect the discs are glazed, which can be helped by going over the surfaces with a flap wheel in an angle grinder. Anything more agressive is a definite no, though.
Personally I replace discs and pads as a full set, but I don’t know if the Ducato kit is expensive or not.
John