Renault Clio III - Brakes squealing but not worn

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Mon 19 Aug 2019 12:49
Renault Clio III - Brakes squealing but not worn - Bob Rock

My Clio III has started squealing under light brake pressure. The front discs and pads were last done in Feb 2018 and still have plenty of life in them, and the rear discs and pads were done in Feb this year.

I first noticed the squeal shortly after the rear brakes were done, but it was only once in a while so I thought they probably just needed to bed in. Unfortunately it has recently become worse to the point of being annoying so I've had the all the calipers and pads out, applied copper paste to the rear and ears of the pads and made sure the clips are in properly. This has made zero difference.

I would normally go back to the garage, but the most recent set was done by a friend for cash so I don't really want to bother him.

One thing I did notice was one of the front pads was an absolute nightmare to get out of the caliper, and back in again. I had to resort to using a rubber mallet and screwdriver as it just wouldn't come willingly. Even with copper paste applied, it didn't slide snugly back into place and needed some persuasion with the mallet again. I wonder if this could be contributing in some way to the squealing?

Any advice much appreciated, thanks.

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Mon 19 Aug 2019 12:59
Renault Clio III - Brakes squealing but not worn - bathtub tom
One thing I did notice was one of the front pads was an absolute nightmare to get out of the caliper, and back in again. I had to resort to using a rubber mallet and screwdriver as it just wouldn't come willingly. Even with copper paste applied, it didn't slide snugly back into place and needed some persuasion with the mallet again. I wonder if this could be contributing in some way to the squealing?

That doesn't seem right to me. Could you have a sticky piston, caliper or slider?

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Mon 19 Aug 2019 13:25
Renault Clio III - Brakes squealing but not worn - gordonbennet

That doesn't seem right to me. Could you have a sticky piston, caliper or slider?

Thats where my money goes, fetch all the pads out again and operate the piston(s) in and out several times until they free moving, if tight/sticking it is permissable to gently lift the rubber dust cover and feed some of the correct red brake grease onto the piston itself whilst it's pushed out, a thin cotton bud is ideal for this, just a light smear will suffice, also make sure the sliders, probably pins, are free so the caliper can move freely as wear takes place, again the correct grease is fine for lubing sliders....note if the piston itself is rusting inside the dust cover then a recon caliper might be on the cards.

That pad that needed hammering in has to come out and it has to be reasonably easy to slide into place, if the pad rests on a stainless spring fitting (those little sprung clips between caliper and steel part of pad) what can happen is the caliper itself corrodes slightly so gunge gets under the spring fitting, the answer is to remove those clips, they usually prise off, then scrape and wire brush the caliper and the clips to get rid of the crud and refit, again a slight wipe of brake grease will help here...and hopefully then the pad will slide in nicely, it must be a snug but not tight fit in place.

Sometimes aftermarket pads can be tight even if everything is clean, and you might need to scrape the paint off the edges of the pad metal, but usually its simply a build up of salty corrosion crud that causes these issues.

Note, its remote but possible the wrong pads have been put in, either end, so maybe make a note of the part numbers and dimensions whilst you have them out and double check online, this was always a particular issue with French cars at one time and i always took the old ones as patterns because there could be several possibles, most cars there will be more than one possible pad unless you own something like a mk1 Aygo where i've only ever seen one type available.

Edited by gordonbennet on 19/08/2019 at 13:32

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Tue 20 Aug 2019 12:36
Renault Clio III - Brakes squealing but not worn - Bob Rock

Thanks for the suggestions all.

Will have a crack at this over the weekend and report back.

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Tue 17 Sep 2019 07:19
Renault Clio III - Brakes squealing but not worn - edlithgow

Thanks for the suggestions all.

Will have a crack at this over the weekend and report back.

Not sure what's with that last post. (Spam gone sour?) so I'll ignore.

Just to add to the above that I've seemed to get good results using aluminium (foil or bits of can or TV aerial, by hand or in a power drill) to rub down brake parts. Doesn't make grit, can be made to conform to surfaces well, and may leave a corrosion resistant residue even in the abscence of a binder.

My other slightly unconventional trick in this context is to wrap PTFE tape around the pins as well as (silicon) greasing them.

A possible caveat might be that IF the brakes ever get REALLY hot this MIGHT release fluoric acid, which is nasty stuff, but since you can apparently buy (Volvo) brake grease with PTFE in it (Not here of course. No brake grease is available here AFAIK) this apparently doesn't bother the Swedes/Chinese.

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Mon 16 Sep 2019 13:28
Renault Clio III - Brakes squealing but not worn - Gabar

Thats where my money goes, fetch all the pads out again and operate the piston(s) in and out several times until they free moving, if tight/sticking it is permissable to gently lift the rubber dust cover and feed some of the correct red brake grease onto the piston itself whilst it's pushed out, a thin cotton bud is ideal for this, just a light smear will suffice, also make sure the sliders, probably pins, are free so the caliper can move freely as wear takes place, again the correct grease is fine for lubing sliders....note if the piston itself is rusting inside the dust cover then a recon caliper might be on the cards.

That pad that needed hammering in has to come out and it has to be reasonably easy to slide into place, if the pad rests on a stainless spring fitting (those little sprung clips between caliper and steel part of pad) what can happen is the caliper itself corrodes slightly so gunge gets under the spring fitting, the answer is to remove those clips, they usually prise off, then scrape and wire brush the caliper and the clips to get rid of the crud and refit, again a slight wipe of brake grease will help here...and hopefully then the pad will slide in nicely, it must be a snug but not tight fit in place.

Sometimes aftermarket pads can be tight even if everything is clean, and you might need to scrape the paint off the edges of the pad metal, but usually its simply a build up of salty corrosion crud that causes these issues city to city mileage

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Note, its remote but possible the wrong pads have been put in, either end, so maybe make a note of the part numbers and dimensions whilst you have them out and double check online, this was always a particular issue with French cars at one time and i always took the old ones as patterns because there could be several possibles, most cars there will be more than one possible pad unless you own something like a mk1 Aygo where i've only ever seen one type available.

my issue got solved!!

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