I'm looking some advice regarding the brake judder on my 2005 CLK.
Only medium to heavy braking shows the problem: a pronounced juddering as if the whole front suspension is falling apart, felt through the steering wheel and also audible.
Light braking & emergency stops are fine, as is normal driving, steering etc.
The problem has developed gradually over the last 6 months/7K miles or so.
None of the changed items have made the slightest difference to the problem.
While the worn ARB bushes are the obvious suspect, I'm worried that they're worn because of the vibration rather than causing it.
If that doesn't work, it'll be the trailing suspension arms next, then possibly new/recon calipers.
Thinking that one of the caliper pistons might be sticking, I gave them a careful test with the pads removed - the top/trailing piston moves out before the lower/leading piston moves. However, since this happens in exactly the same way on both capiers, I suspect it's a design feature rather than 4 sticking pistons.
A search of the forum hasn't thrown any light on the matter. Any suggestions?
Thanks,
Ian.
Only medium to heavy braking shows the problem: a pronounced juddering as if the whole front suspension is falling apart, felt through the steering wheel and also audible.
Light braking & emergency stops are fine, as is normal driving, steering etc.
The problem has developed gradually over the last 6 months/7K miles or so.
I've replaced the pads and rotors, cleaned & filed the hubs so that runout is less than 0.04 mm measured at the edge of the disks (spec is 0.12mm).
Wheel bearing end float is somewhere between 0.01 and 0.02mm (it's difficult to measure, even with a dial gauge)
The disk rotors are Brembo, the pads Pagid, replaced 2 weeks ago.
The leading suspension arms and ARB drop links were replaced at the same time (they were an advisory, so were going to be changed anyway).
The brake hoses are stainless steel over PTFE inners, now about 8 years old, but I can't think of a reason why they might be the problem.
The struts, springs and top mounts were replaced 2 years ago.
Tyres were replaced 2 months ago.
I noticed that the ARB bushes were worn, so I'll be replacing them this weekend.
Wheel bearing end float is somewhere between 0.01 and 0.02mm (it's difficult to measure, even with a dial gauge)
The disk rotors are Brembo, the pads Pagid, replaced 2 weeks ago.
The leading suspension arms and ARB drop links were replaced at the same time (they were an advisory, so were going to be changed anyway).
The brake hoses are stainless steel over PTFE inners, now about 8 years old, but I can't think of a reason why they might be the problem.
The struts, springs and top mounts were replaced 2 years ago.
Tyres were replaced 2 months ago.
I noticed that the ARB bushes were worn, so I'll be replacing them this weekend.
None of the changed items have made the slightest difference to the problem.
While the worn ARB bushes are the obvious suspect, I'm worried that they're worn because of the vibration rather than causing it.
If that doesn't work, it'll be the trailing suspension arms next, then possibly new/recon calipers.
Thinking that one of the caliper pistons might be sticking, I gave them a careful test with the pads removed - the top/trailing piston moves out before the lower/leading piston moves. However, since this happens in exactly the same way on both capiers, I suspect it's a design feature rather than 4 sticking pistons.
A search of the forum hasn't thrown any light on the matter. Any suggestions?
Thanks,
Ian.
