3 hours ago, sepulchrave said:

 

Why do you need those, they don't do anything?

Caliper works through those bushings. Issue is caliper which is (maybe) rattling. As from my Furby, during 12 years and 275k km never replaced not guide pins, not guide bushings- nothing rattled on my FSIII brakes.

10 minutes ago, indars said:

Caliper works through those bushings. Issue is caliper which is (maybe) rattling. As from my Furby, during 12 years and 275k km never replaced not guide pins, not guide bushings- nothing rattled on my FSIII brakes.

 

No it doesn't.

 

Those pins in the rubber bushings purely keep the caliper from falling off, all the load is taken by the carrier assembly into which the pads are inserted, those pins carry no load whatsoever and do not wear out, that's why they're rubber so that they can accommodate any slight misalignment when the caliper clamps down on the pads.

2 minutes ago, sepulchrave said:

 

No it doesn't.

 

Those pins in the rubber bushings purely keep the caliper from falling off, all the load is taken by the carrier assembly into which the pads are inserted, those pins carry no load whatsoever and do not wear out, that's why they're rubber so that they can accommodate any slight misalignment when the caliper clamps down on the pads.

No, bushes carry load. Little but anyway. Then why TRW system pins and caliper (with built-in bushes) worn out? When brakes are applied, caliper tends to turn to one side since this is not fixed caliper but sliding one.

I suggest to look closer on this. On old brakes pad's ear worns out this place and distance (can be seen on client's photo) can cause rattle.

On 12/07/2023 at 01:12, TMB said:

The only thing I use on the pins/bushes is ceramic brake grease. I know some people use copper grease too. It's a bit of a puzzler if it's not the pads. Are you sure it's not the drop links as they are notorious for knocking/rattling?

ATE says not to grease their rubber bushes. I greased them everytime (just need to use neutral-to-rubber grease) and all ok. My BMW friends doesn't grease them because "pull-back action works no more", ahaha.

9 minutes ago, indars said:

ATE says not to grease their rubber bushes. I greased them everytime (just need to use neutral-to-rubber grease) and all ok. My BMW friends doesn't grease them because "pull-back action works no more", ahaha.

 

You don't need to grease them because rubber is self-lubricating, you should try listening occasionally!

21 minutes ago, sepulchrave said:

 

You don't need to grease them because rubber is self-lubricating, you should try listening occasionally!

Old dry rubber bush is not self-lubricating no more- but who cares since brakes works ok with or without grease. About ATE brake system where pads sits on carrier and caliper tends to turn less (and therefore it's enough just with soft rubber bushes)- good point, haven't thought about this before. Thank you for info!

Edited 10 September, 20232 yr by indars
Updated comment

41 minutes ago, sepulchrave said:

 

You don't need to grease them because rubber is self-lubricating, you should try listening occasionally!

 

I'm sure there's sometimes a bush for the pins inside the rubbers? I remember seeing nylon type ones on some cars.

3 hours ago, sepulchrave said:

Those pins in the rubber bushings purely keep the caliper from falling off, all the load is taken by the carrier assembly into which the pads are inserted, those pins carry no load whatsoever and do not wear out, that's why they're rubber so that they can accommodate any slight misalignment when the caliper clamps down on the pads.

 

I've been working on these types of calipers since forever, all of my cars for as long back as I can recall have had this setup.

 

In all that time it what you explain had never dawned on me, it makes complete sense and I'm amazed that as an engineering designer I had not appreciated it, thanks for teaching an old dog a new trick!

 

I have never ever considered greasing them, when the pins have been really reluctant to come out I may have used a dash of WD whatever to reassemble.

I thought I might update the thread,  I ended up putting some liqui moly anti squeal paste on the points of contact between the caliper and the caliper carrier (hub assembly) which  mostly solved the issue, there's still some slight clanking when driving over very rough surfaces like uneven gravel roads or potholes but for the most part the brakes have quieted down.

 

Having played around with brakes it seems to me that it's really just a design flaw, there's very tiny gap between the caliper and caliper carrier seen in the photo (less than 1 mm) and that play is what causes the clanking. Most other floating brake caliper of this design usually have a spring clip on the end which puts slight tension on the caliper preventing it from vibrating too much but these admittedly cheap calipers don't have that. Some have suggested changing out the rubber boots where the guide pins slide or greasing guide pins but that doesn't eliminate the play in caliper, also as mentioned they were a very tight fit to begin with so changing seems pointless, really you need some form of spring tension to stop excess movement.

 

I will eventually replace the rotor and caliper when they wear out so I might give an aftermarket brand like ATE or Pagid a try instead of going genuine VW, we'll see if that makes any difference.

Edited 17 September, 20232 yr by Carproblems