LCR knocking at low speed when brakes are applied

[747_727]

Had this problem for over a year now. I replaced both wishbones as the bushes were migrating but the knocking noise is still there. Seems to be coming from the brakes as you can hear knocking from both sides when breaking at low speed. It does it everytime you apply the brakes. Any ideas what's causing it?

 

[Bouncerbeater]

First thought would be warped discs but maybe that's just too simple

 

[747_727]

Don't think it warped discs as the brakes don't vibrate when breaking. It sounds very metallic like something is loose or warn.

 

[Rivva]

Do you hear the knocking when going over rough ground or speed bumps? Turned out to be track rod ends for me.. although it could be the pads moving in the calipers?

 

[747_727]

No only when breaking. Which makes me think it must be brake releated. The pads are very low so I will be replacing them soon maybe that will cure it if it's a lose pad?

 

[Matty589]

No only when breaking. Which makes me think it must be brake releated. The pads are very low so I will be replacing them soon maybe that will cure it if it's a lose pad?

It might be the pads moving if they are low I would try a set of good pads.

 

[Azza_]

watch out for worn calipers too, some aftermarket pads are also a poor fit, try kicking the wheel when stationary (hard) listen for a rattle if its there get someone to stamp on the brakes then kick the wheels again

 

[Dave_c85]

My car does this now and again, especially when I apply the brake when reversing, it makes a metallic noise but just once. I have no clue what it is

 

[JamieF]

Worn rack/track rods (not track rod ends)can give the same symptoms, jack the front end up and grab the wheel at the 3 and 9 postion, if there is movment, feel both the rack ends and track rods, for the rack rods joint, feel the boot on the end of the steering rack, you will feel a big lump in the middle, this is where the joint is, get someone to shake wheel and feel for movement.

 

[andycupra]

as mentioned, there is a known issue whereby the pads can move in the calipers.
many LCRs have this issue when first braking after a change of direction, IE the first brake when you start reversing, then the first time brakes are used when you then go forwards.

I remember reading how someone had 'encouraged' the pad pins on the Brembos to stop this movement.

 

[747_727]

I will be replacing the pads and discs soon and I will check the rack ect when I'm doing it. I didn't think about track rods. Hopefully it's the pads though as my car does clunk when you reverse and when you first brake after going forwards again.
Thanks for your help.