Floating Brakes

[konman]

heres a question, do the brake disks on the VR4 "float" ? what i mean is they go over the 5 bolts, but is there something that holds them onto the hub apart from the caliper? ive had this weird vibratrion cruising along the motorway so i finally decided to take the wheel off and have a look. frontdrivers side all fine, front passenger side also fine i thought, but then felt the brake disk and it moved back and forth, weird. the car went in for a service on its stearing rack a couple of months ago so im wondering if the mechanic forgot to put a bolt back on or something. as far as i can tell the big mother bolt in the middle is still on.... can any one help ? /help /help

[SGHOM]

yes..... we have 'floating discs' /yes
the only thing holding them in place is the wheel.

[konman]

aaaaahhhhaaaaaa thanks for that, was a bit worried for a sec, back on the search for the mysterious vibration.

[dickytim]

the tension of the wheel being done up should hold the disk onto the hub, I am pretty sure it is ment to be that way, the vibration could be "warped" disks, if you have over cooked your brakes a couple of times, or even if you leave your foot on the brakes after stopping from a decent speed this could leave deposits on the disk. I found changing my worn ball joints helped with my vibrations.

[Kieran]

/EDIT

Sorry - brain misfired there....... Stupid question now deleted and normal service will be resumed!! :embarasse

[I-S]

No, the discs aren't floating. Floating discs have special mechanisms that allow them to move side-to-side. These are just held on by the wheel.

There's two possibilities... One is the warped disc, which seems to afflict the galants a lot and is most likely. Other is that if it suddenly started happening after the steering rack work was done then try taking the disc off, rotating it one bolt hole around and putting it back on, repeating until it works better. If it doesn't, clean the hub carrier and the back of the disc.

[Kenneth]

Here is a picture of a floating disk
http://www.conti-online.com/generator/www/com/de/continental/portal/themen/presse_services/pressemitteilungen/img/actuation_foundation_uv;property=original.jpg


As you can see, the assembly is actually 2 pieces. The "floating" piece is the friction surface and is connected via shims to the carrier. This allows for a very small amount of side to side movement (as previously posted) which results in a more even contact between brake pad and disk. This gives more consistent brake feel, allows better modulation and promotes more even pad wear.

I'm not 100% sure on how it works temperature wise, but I believe that the disk also heats more evenly and can run cooler.

Another benefit is that the carrier does not have to be of the same material as the friction surface which can save weight.

Only downside that I am aware of is that they tend to "chatter" at low speed which some people dont like.