problem with brake disc.

[L0veZHP]

I have my hand/emergency brakes on and my brake disc still moves. What do I need to solve this problem?

[danewilson77]

I suck in this area. I don't want you to think I am ignoring you...cuz I'm not.

[danewilson77]

Could it just be the brake shoes?

You've done this...right?

Pull up on the e-brake boot till it pops off. Then tighten the two cables with a wrench. Make sure the rear wheels still roll freely when the e-brake is off.

[Mtnman]

Would he just need to tighten the cable that is connected to the ebrake? Lovezhp, if you put the brakes on with your foot, do the pads engage? If they do, i would think either your cable from the ebrake is broken, or it needs to be tightened. Right guys?

[L0veZHP]

Alright ill try to see if thats the problem im at home now and its late over here... Thanks a lot guys.. i Think its the ebrakes cable tho

[L0veZHP]

I need a lesson on brakes. =/ i have no idea about senors and pads, rotors? ebrake line? can anyone explain? please.

[mimalmo]

Time for a new e-brake shoe.

[Mtnman]

Yeah. Listen to mimalmo and dane. I know just enough to get u in trouble!

Sent from my DROID2 GLOBAL using Tapatalk

[danewilson77]

OK.....so here is a pic of your e brake system. The brakes on your lawn mower are probably bigger...

http://i1015.photobucket.com/albums/af278/nicee46/Maintenance%20and%20Misc/FireShotcapture010-RealOEM_comBMWE46330iPARKINGBRAKE_BRAKESHOES-www_realoem_com_bmw_showparts_do_modelEV53mospid47 725btnr34_0768hg34fg40.png

IN A NUTSHELL
Front and rear brakes are basically the same. Each system has a piston that is fed with brake fluid via a brake line. As you press on the brake....fluid pressure is sent down the brake line to the brake caliper piston. This will move the inner portion of the of the brake caliper and will squeeze the rotor between the two pads.....

The outer brake pad and caliper portion are stationary. The caliper guide bushings are what keeps the inner moveable caliper and brake pad nice and parallel as you press the brake.

SS brake lines are better because they don't "flex" under dynamic breaking...like the rubber ones do...therefore they are much more responsive.

Also recognize...you have brake pad wear sensors on the front right and rear left brake pads.

http://i1015.photobucket.com/albums/af278/nicee46/Maintenance%20and%20Misc/FireShotcapture011-RealOEM_comBMWE46330iFrontwheelbrake-Brakepadsensor-www_realoem_com_bmw_showparts_do_modelEV53mospid47 725btnr34_0757hg34f.png
The rotor thickness spec is stamped onto the rotor hat should you ever need this info.

[Nivo]

I have my hand/emergency brakes on and my brake disc still moves. What do I need to solve this problem?

maybe the shoes are worn or simply the cables need adjustment.
easiest fix is the cable adjustment.

[L0veZHP]

when i buy new rotors do i need to get both front and back? or just front?

[Nivo]

when i buy new rotors do i need to get both front and back? or just front?

with new rotors always get new pads to seat with the rotors. i recommend getting the rotors in sets, either both fronts or both rears.

you might need to use a micrometer on the rotors and see if they are at their minimum thickness. If you see deep grooves, gouges or overheating marks I would replace them.

[danewilson77]

with new rotors always get new pads to seat with the rotors. i recommend getting the rotors in sets, either both fronts or both rears.

you might need to use a micrometer on the rotors and see if they are at their minimum thickness. If you see deep grooves, gouges or overheating marks I would replace them.

Just to round this out....the min rotor thickness is stamped on the rotor hat. A pic for you my friend.

http://i1015.photobucket.com/albums/af278/nicee46/Maintenance%20and%20Misc/rotor_measurement.jpg

And a good bedding procedure can be followed below.....under technical....then how to bed brakes....

http://www.zeckhausenracing.com/

[Smilez]

All these fellas are right.

[Rovert]

For my car the brake rotor wells where the E-brake shoes contact have glazed up and are very smooth so that the ebrake shoes can't grab onto much. I took my rotors off and used sandpaper to rough it up at much as possible with not much success. So the only solution is to get new rear brake rotors. For now I don't part on super steep inclines/declines...haha. And ALWAYS park your car in gear!

[danewilson77]

You can still get the performance rears for cheap.....


For my car the brake rotor wells where the E-brake shoes contact have glazed up and are very smooth so that the ebrake shoes can't grab onto much. I took my rotors off and used sandpaper to rough it up at much as possible with not much success. So the only solution is to get new rear brake rotors. For now I don't part on super steep inclines/declines...haha. And ALWAYS park your car in gear!



Sent from my Droid using Tapatalk

[LivesNearCostco]

Can someone tell me the minimum rotor thickness of the stock rear rotors? I can see the minimum thickness number stamped on my front rotors (I think it's 23.4mm or 24.3mm) and my front rotors are comfortably above this number. But I cannot find the stamped number on my rear rotors, possibly hidden by corrosion.


Just to round this out....the min rotor thickness is stamped on the rotor hat. A pic for you my friend.

http://i1015.photobucket.com/albums/af278/nicee46/Maintenance%20and%20Misc/rotor_measurement.jpg

And a good bedding procedure can be followed below.....under technical....then how to bed brakes....

http://www.zeckhausenracing.com/

[Dave1027]

Minimum thickness is usually stamped on the rotor somewhere.

[LivesNearCostco]

Yes, but I can't find the stamping on my rear rotors. Do you happen to know what it is for the ZHP rear rotors?

[danewilson77]

Yes, but I can't find the stamping on my rear rotors. Do you happen to know what it is for the ZHP rear rotors?

Front-20.4mm
Rear-17.4mm

[danewilson77]

Also found this...

[LivesNearCostco]

Ah thanks, Dane. I remember seeing the front number stamp and my fronts are around 21mm now (or were before last 3 track days). Rears I'll measure soon.

That SIB was interesting--suggests cross-drilled rotors cannot handle as much thickness loss as plain rotors.

[terraphantm]

Front-20.4mm
Rear-17.4mm

That sounds low. I could have sworn it was 23.4 and 20.4

[danewilson77]

Yeah...this is more like it.

23.4mm front

20.4mm rear

The "17" seemed low to me as well.

17.4 spec is for 323/325/328

[danewilson77]

Using the SIB > Nominal size - 2.4 (non ///M and non perf) or - 1.6 (///M and/or perf)

NOTE: Because many of us have aftermarket rotors, the safe bet is to know these specs, but check the stamped spec on the rotor hat (if you can)

For BMW E46 330i/Ci

Front Perf = 25mm - 1.6mm = 23.4mm min-spec

Rear Perf = 22mm - 1.6mm = 20.4mm min-spec

Front ventilated disc = 25mm - 2.4mm = 22.6 min-spec

Rear ventilated disc = 22mm - 2.4mm = 19.6mm min-spec

Front Perf
http://i1015.photobucket.com/albums/af278/nicee46/Maint%20and%20Misc%20II/330iFrontPerf.png (http://s1015.photobucket.com/user/nicee46/media/Maint%20and%20Misc%20II/330iFrontPerf.png.html)

Rear Perf
http://i1015.photobucket.com/albums/af278/nicee46/Maint%20and%20Misc%20II/330iRearPerf.png (http://s1015.photobucket.com/user/nicee46/media/Maint%20and%20Misc%20II/330iRearPerf.png.html)

Front ventilated disc
http://i1015.photobucket.com/albums/af278/nicee46/Maint%20and%20Misc%20II/330iFrontvent.png (http://s1015.photobucket.com/user/nicee46/media/Maint%20and%20Misc%20II/330iFrontvent.png.html)

Rear ventilated disc
http://i1015.photobucket.com/albums/af278/nicee46/Maint%20and%20Misc%20II/330irearvent.png (http://s1015.photobucket.com/user/nicee46/media/Maint%20and%20Misc%20II/330irearvent.png.html)

For BMW E46 323/325/328i

Nominal size is 22mm front vetilated disc. and rear is 19mm ventilated disc.

Therefore;

Front ventilated disc
22mm - 2.4mm = 19.6mm min-spec

Rear ventilated disc
19mm - 2.4mm =16.6mm min-spec

http://i1015.photobucket.com/albums/af278/nicee46/Maint%20and%20Misc%20II/323325328frontventdisc.png (http://s1015.photobucket.com/user/nicee46/media/Maint%20and%20Misc%20II/323325328frontventdisc.png.html)

http://i1015.photobucket.com/albums/af278/nicee46/Maint%20and%20Misc%20II/323325328rearventdisc.png (http://s1015.photobucket.com/user/nicee46/media/Maint%20and%20Misc%20II/323325328rearventdisc.png.html)

[LivesNearCostco]

Interesting. I do not have performance rotors, mine are plain vented (rears kind of rusty, which might be why I can't see the stamped minimum). But not sure if my rotors are OEM or aftermarket... I haven't changed them in 45,000+ miles but I know one of the previous owners changed them. Maybe tomorrow I can re-measure front and back rotor thickness and go after a rear rotor with a wire brush in search of the stamp.

I have NIB plain vented rotors from UUC sitting in the garage... bought them in late 2010 and early 2011 and been carrying them around for over 2 years, waiting for my current rotors to wear out. Obviously I bought those too early!

[danewilson77]

Interesting. I do not have performance rotors, mine are plain vented (rears kind of rusty, which might be why I can't see the stamped minimum). But not sure if my rotors are OEM or aftermarket... I haven't changed them in 45,000+ miles but I know one of the previous owners changed them. Maybe tomorrow I can re-measure front and back rotor thickness and go after a rear rotor with a wire brush in search of the stamp.

I have NIB plain vented rotors from UUC sitting in the garage... bought them in late 2010 and early 2011 and been carrying them around for over 2 years, waiting for my current rotors to wear out. Obviously I bought those too early!

is there a spec stamped on the new UUC rotors? Just curious.

[LivesNearCostco]

Just looked at new (from a few years ago) UUC rotors, says minimum is 20.4mm. They measure at about 22.3mm new with the black anti-corrosion coating on the friction surfaces. (Unless I'm measuring the front rotors by mistake.) That matches what you posted for the rear performance rotors, only mine are plane vaned, no cross-drilling.

Edit 1: The UUC fronts are 25mm wide (actually around 24.95mm) and say minimum thickness is 23.4 or 22.4, don't remember now.
The numbers are stamped right along the edge of the disk near the vents.

Edit 2: On my current rear rotors, finally found it. Had to clean a bit of rust off the edge with a wire brush. It also says minimum thickness is 20.4mm but they currently have more than 21mm thickness. Won't need the new UUC rotors for a while; just taped their boxes shut again and put them back on the shelf.