Qube
11-04-2006, 04:24 PM
Well, last year Dec, I had issues with sticking calipers:
http://www.bimmer.info/forum/showthread.php?t=16630&highlight=caliper+sticking
Per Whit's advise, it looks like I've outlived the lube and time to replace the caliper...
Qube, once there's rust on the piston surface (contact area between the caliper housing itself and the piston), it's done. The piston has a chrome surface. Rust is indicative of scoring through that surface, and there may also be damage to the piston housing.
As you may know, brake fluid is highly corrosive stuff. Once it comes into contact with what surface has been scraped from the piston, you'll have the same problem all over again.
best, whit
On that note, these are the symptoms about the driver (LHD) front side:
much more brake dust (damn!)
very VERY minor notice that SOMETIMES a slow rolling stop will be abrupt... but subtle enough that barely notice. SOMETIMES on minor incline the car will hold in neutral, so something is sticking.
on a short trip, noticed driver side rotor is hotter than passenger (touch test, yeah it was hotter)... but not so hot that the wheels are scorching like last year.
all other pads are chamfered wear but this one is flat against the rotor. not saying the others are normal, but this one is different
ATF is leaking slowly, but very messy :( not much to do with the brake issue though
woooooooooooooo metal sound (not sharp) from seemingly that side on CERTAIN right turns only
So given most of the items on the list, it's time to replace the caliper, right? I'm a little perplexed by the last item on the list. Can I justify it as related to the probably sticking / dragging caliper issue?
Would I do good to replace fronts as a set or just that one?
http://www.bimmer.info/forum/showthread.php?t=16630&highlight=caliper+sticking
Per Whit's advise, it looks like I've outlived the lube and time to replace the caliper...
Qube, once there's rust on the piston surface (contact area between the caliper housing itself and the piston), it's done. The piston has a chrome surface. Rust is indicative of scoring through that surface, and there may also be damage to the piston housing.
As you may know, brake fluid is highly corrosive stuff. Once it comes into contact with what surface has been scraped from the piston, you'll have the same problem all over again.
best, whit
On that note, these are the symptoms about the driver (LHD) front side:
much more brake dust (damn!)
very VERY minor notice that SOMETIMES a slow rolling stop will be abrupt... but subtle enough that barely notice. SOMETIMES on minor incline the car will hold in neutral, so something is sticking.
on a short trip, noticed driver side rotor is hotter than passenger (touch test, yeah it was hotter)... but not so hot that the wheels are scorching like last year.
all other pads are chamfered wear but this one is flat against the rotor. not saying the others are normal, but this one is different
ATF is leaking slowly, but very messy :( not much to do with the brake issue though
woooooooooooooo metal sound (not sharp) from seemingly that side on CERTAIN right turns only
So given most of the items on the list, it's time to replace the caliper, right? I'm a little perplexed by the last item on the list. Can I justify it as related to the probably sticking / dragging caliper issue?
Would I do good to replace fronts as a set or just that one?