Clunking noise when pressing brake pedal.

Toots

I'm having a weird issue when I press the brake pedal on my car - sometimes there's a kind of clunking, twanging noise, and it almost feels like the pedal is catching on something.

I've had it in to two different garages, and both can't seem to find anything wrong. One garage had 3 people test drive it and they couldn't hear it. It's intermittent, so it doesn't happen all the time. Some days it might only happen once or twice, other days it's almost every time I brake.

Has anyone any idea what could be causing it? I'm obviously concerned, seeing as it happens when braking, but nobody has been able to find the cause.

colm_mcm

What car is it?

Toots

God, that would probably be helpful info to add

It's a 2012 Renault Grand Scenic.

Had the front and rear brakes done a couple of months ago, also had rear springs and drop link done on the drivers side.

jmreire

Toots wrote: »

I'm having a weird issue when I press the brake pedal on my car - sometimes there's a kind of clunking, twanging noise, and it almost feels like the pedal is catching on something.

I've had it in to two different garages, and both can't seem to find anything wrong. One garage had 3 people test drive it and they couldn't hear it. It's intermittent, so it doesn't happen all the time. Some days it might only happen once or twice, other days it's almost every time I brake.

Has anyone any idea what could be causing it? I'm obviously concerned, seeing as it happens when braking, but nobody has been able to find the cause.

Might not be the actual brakes at all, but a suspension part? That's what it sounds like. Try it on a smooth road, and then on a rough road, and see if that makes any difference. Clunking could be from a broken coil spring. or shock absorber bushing

bilbot79

I had this once when my brother fitted the wrong kind of wheels to my z3 because he thought they looked great. In reality they were meant for a much bigger car

Toots

Would that be visible if the car was up on a ramp in a garage?

jmreire wrote: »

Might not be the actual brakes at all, but a suspension part? That's what it sounds like. Try it on a smooth road, and then on a rough road, and see if that makes any difference. Clunking could be from a broken coil spring. or shock absorber bushing

Toots

bilbot79 wrote: »

I had this once when my brother fitted the wrong kind of wheels to my z3 because he thought they looked great. In reality they were meant for a much bigger car

Wheels are definitely the correct size, they're the original stock ones.

jmreire

Toots wrote: »

Would that be visible if the car was up on a ramp in a garage?

If you can get it up on a lift, then you will need some one to "Bounce" the car up and down, an have some one underneath looking and listening. Like I said, a quick way to check is to drive it on a rough road, and then a smooth road. If it's a coil spring, it might not be easy to see the break, if it was in at the back. If its on the visible part of the spring, all you might see is a rusty looking crack. And because normally the spring is compressed, you would have to jack the car up and let the wheels hang down. In some cases, the car will be a little bit lower on the side where the spring is broken. Stick your hand in between the top of the wheel and the bottom of the wing, and see if the other side is different.

Xodar

Could be any number of things. What comes to mind is a worn (or badly worn) bushing or a top mount. Could also be a suspension strut.

Noise can travel along the chassis of the car and give the impression it is coming form somewhere that it is not.

It would have to be on a ramp and not a lift as the suspension wouldn't be under stress on a lift.

Is there actual feedback from the pedal (is the feel different) or is it that you have a feeling that it is catching?

jmreire

Xodar wrote: »

Could be any number of things. What comes to mind is a worn (or badly worn) bushing or a top mount. Could also be a suspension strut.

Noise can travel along the chassis of the car and give the impression it is coming form somewhere that it is not.

It would have to be on a ramp and not a lift as the suspension wouldn't be under stress on a lift.

Is there actual feedback from the pedal (is the feel different) or is it that you have a feeling that it is catching?

4 post lift???

Toots

Xodar wrote: »

Could be any number of things. What comes to mind is a worn (or badly worn) bushing or a top mount. Could also be a suspension strut.

Noise can travel along the chassis of the car and give the impression it is coming form somewhere that it is not.

It would have to be on a ramp and not a lift as the suspension wouldn't be under stress on a lift.

Is there actual feedback from the pedal (is the feel different) or is it that you have a feeling that it is catching?

I can actually feel a difference in it, I get it about half way down, then it feels like snags or catches and continues. It doesn't actually stop the pedal, but I can feel it in the pedal as I push down.

Xodar

jmreire wrote: »

4 post lift???

Yes a 4 post, which I consider a ramp, as in you drive the car up onto it and the suspension is under load from the weight of the vehicle.

Toyotafanboi

I'm not saying it is this, but those Scenics and Grand Scenics did have an appetite for front springs, usually at the bottom near the spring seat on the shock body. Often though you'd expect it to be rattling it's nuts off most of the time though.

Could be anything suspension related really.

listermint

Brake master cylinder or the spring on the pedal.

Problem here is inside the cab I'd put money on it.

jmreire

Xodar wrote: »

Yes a 4 post, which I consider a ramp, as in you drive the car up onto it and the suspension is under load from the weight of the vehicle.

I never realized that there was a difference between "Lift's and " Ramp's"....despite having spent a lot of my Life under them...all kind's of 'em..so you live and learn !!! :):)

Toots

listermint wrote: »

Brake master cylinder or the spring on the pedal.

Problem here is inside the cab I'd put money on it.

Is the spring something I could check myself?

jmreire wrote: »

I never realized that there was a difference between "Lift's and " Ramp's"....despite having spent a lot of my Life under them...all kind's of 'em..so you live and learn !!! :):)

The one they had my car up on was the kind that the wheels drop down, if that makes sense. So the car was lifted up to about head height, but the wheels weren’t resting on anything.

jmreire

Toots wrote: »

Is the spring something I could check myself?



The one they had my car up on was the kind that the wheels drop down, if that makes sense. So the car was lifted up to about head height, but the wheels weren’t resting on anything.

Yes, these kind of lifts, are known as 2 post wheel free lift's, and very common in tyre sale's garages. But not so
good for what you want. You need all the weight of the car on it's wheels, then with someone "bumping" the car up and down on on its springs, and some one else listening for any noises, and pin pointing the source. There are several good suggestion's here from posters as to the possible source, including one suggestion that it may be internal, linked to the brake pedal, If it is this, then the noise would be noticeable from inside the car. It could also be that this particular make of car has a known problem with this kind of "Knocking / Banging". Don't worry, you will find it sooner or later, and hopefully sooner. Good Luck with it,.

listermint

Toots wrote: »

Is the spring something I could check myself?



The one they had my car up on was the kind that the wheels drop down, if that makes sense. So the car was lifted up to about head height, but the wheels weren’t resting on anything.

Pull the seat back get down into the footwell and have a look around at the brake pedal force it with your hand and see if there's feedback.

Toots

Thanks for all the help so far, everyone! Really hoping I do find it soon because it's driving me insane.

I'll have a look at the pedal this evening, at least that's something I can do myself. I hope it's that because I've spent a fortune on the car so far this year, between brakes, the rear springs and then €560 for tyres.

Sam Quentin

Any chance one of the front calipers is just not tightened properly?

Toots

Sam Quentin wrote: »

Any chance one of the front calipers is just not tightened properly?

Could I check/fix that myself or would that need the car on a lift?

Max Moment

Check the mats aren’t catching the pedal too

Sam Quentin

Toots wrote: »

Could I check/fix that myself or would that need the car on a lift?

You can check it on the ground, take the wheel off and with both hands see if you can move the caliper forward or back, it shouldn't move and if it does then it'll definitely clunk when braking,. So then you gotta tighten the caliper pins from behind/inner side of the caliper. Obey all safety procedures while you have the car up jack, axle stands etc., especially as you will be using force to try to move the caliper.