Clunk after going backwards then forwards

[Andy03]

Hi all

my 172 cup has developed a problem I think from the front brakes but could be wrong. What happens is when going from reverse to forwards there is a clonk and I can't work out what it is. One idea I have had is its from the brake pads I have just replaced the discs and pads I believe I did everything back up ok but the old pads had a shim with them where as the new ones do not

for the record it is a 172 cup so no abs however as a reference the clonk sounds quite a bit like a loud abs self test
Any help with this mystious clonk would be greatly appreciated.

 

[Gandi69]

pads rattling around in the caliper could be it, some brands of pad seem to do this as they arent the greatest fit in the caliper. Does it do it only when you touch the brake pedal?

 

[Andy03]

pads rattling around in the caliper could be it, some brands of pad seem to do this as they arent the greatest fit in the caliper. Does it do it only when you touch the brake pedal?

the pads were brembo I may try another brand in the future I quite fancid trying the ds2500. But yeah I only does it when, for example I've reversed off my drive braked then gone forward and braked again after that the brakes are fine

 

[Gandi69]

Mine does exactly that. The only thing i've not changed on it that could maybe cause it is the inner tie rods but as it only does it when the pedal is applied I'm going with it being my pads - even though I've had 3 different sets!

 

[bashracing]

Knackered Cv joint or subframe bolts loose?

 

[D4w5on]

have u checked top engine mount. i had same issue was top mount knackerd

 

[Ianboom]

My brembo pads do this, better than having them seized in the caliper!

 

[Mar172]

Hi all

my 172 cup has developed a problem I think from the front brakes but could be wrong. What happens is when going from reverse to forwards there is a clonk and I can't work out what it is. One idea I have had is its from the brake pads I have just replaced the discs and pads I believe I did everything back up ok but the old pads had a shim with them where as the new ones do not

for the record it is a 172 cup so no abs however as a reference the clonk sounds quite a bit like a loud abs self test
Any help with this mystious clonk would be greatly appreciated.

slide the shims back in

 

[AlexW]

As said, Brake pads. Buy new shims and clean up the calipers and you'll solve it.

 

[MicKPM]

As he said, pads moving in the carrier due to no shims. Nothing too major to worry about

 

[welshname]

Usually ball joints when this happens IMO.

 

[MicKPM]

Could also be the bottom BJ but as he's just had brakes and no new shims I'd wager pads. The easiest way to confirm would be to get a mate watch the wheel and brake pads whilst you slowly drive forwards/backwards and hit the brakes.

If the pads move and he can hear the noise it's pads. If the pads stay in place but the wheel shifts position relative to the wheel arch (and it will be minimal) it's the BJ

 

[welshname]

Could also be the bottom BJ but as he's just had brakes and no new shims I'd wager pads. The easiest way to confirm would be to get a mate watch the wheel and brake pads whilst you slowly drive forwards/backwards and hit the brakes.

If the pads move and he can hear the noise it's pads. If the pads stay in place but the wheel shifts position relative to the wheel arch (and it will be minimal) it's the BJ

Yep good shout. Just thought I'd throw the possibility out there as no one else had

 

[AlexW]

BJ made me laugh. How immature.

 

[MicKPM]

I find ordering "Siemens" parts comedy gold to

 

[STEVE.M]

I find ordering "Siemens" parts comedy gold to

Captain Pugwash and his salty seamen.

 

[AlexW]

I find ordering "Siemens" parts comedy gold to

Honestly hadn't thought of this before now!

Ruined it now!

 

[Andy03]

Thanks for all the replies guys I've sussed it now there's 1-2mm of play between the pads and calliper mount so I need to shim it. I'm assuming that Renault shims will do the job. So it should just be a quick message to Renault Wolverhampton.

 

[Andy03]

I also read today that the cup originally had slightly larger pads. And the ds2500 pads come in two different sizes to mirror this. The larger set would definitely not need shims as they are that much bigger. Anyone else seen this?

 

[MicKPM]

The brake pads are the same across the range although some manufacturers backplate dimensions are a little more generous than others which is why you should always check/size brake pads when fitting them to stop them seizing.

 

[_WILL_]

I also read today that the cup originally had slightly larger pads. And the ds2500 pads come in two different sizes to mirror this. The larger set would definitely not need shims as they are that much bigger. Anyone else seen this?

You have to cut down DS2500 to fit and should run without shims and they will squeal and knock (nither of these bother me and they are worth the trade off for track use).

If you don't track the car then the Brembo OEM replacement pads and Brembo HC discs are more than enough for the road. If you are cooking them then you a probably braking too much!!!!! I did a 12 car last year and was pushing hard and they were fine. Re-fit shims to the pads you have and bit of copper grease and you will be fine.

I have bever had replacement shims, I just use the old ones, I have even kept them in case I go back to standard pads over the winter.

 

[Andy03]

Unfortunately I binned the old pads with the shims still on. Bit of a 'd'oh' moment with hindsight! I've seen replacement shims for sale on eBay and I've emailed Wolverhampton Renault so thankfully I can get them. Thanks for the info on the ds2500s it certainly put getting them into perspective.