How to remove siezed brake rotor

[AllyBassman]

Hi all,

Looking for some advice, I'm in the process of changing my pads and rotors on a BMW E90,

Fronts were fine, but I got stuck on trying to remove the rear passenger side disc. I think it's seized onto the hub. I did think it has the handbrake at first, but I am able to spin the rotor freely so i can only think that it's siezed on as it will not move at all even with some 'gentle' help from a hammer.

I'm a newbie DIY'er so be kind! I really would like to avoid taking it to the proffessionals and admitting defeat!

Cheers,

[Richyvrlimited]

as it's also a drum for the handbrake mechanism there's likely a lip that the shoes are getting caught on.

back the handbrake adjuster right off to get yourself more clearance.

[Chainsaw Rebuild]

Rear discs can be a pain because like our mate above says, if there is an internal handbrake it will need backing off.

It can also be the disc is corroded onto the hub. Once you are sure its not the handbrake holding it you can whack it on the braking surface to free it off, try working around the disc. With mine I had to give it a rather hard whacking!

[Mr2Mike]

Is the disc moving at all, or is it solidly bonded to the hub? If it's moving a few millimetres before going tight then it's probably the handbrake. If there is no movement then it's more likely corrosion holding it, so more persuasion is required.

This is all assuming you've removed the 6mm socket head screw that holds the disk to the hub whilst the wheel is removed...

[AllyBassman]

Thanks for all of the replies,

yes, the 6mm retaining screw was removed. I did back off the handbrake off also. Even with the hardest of hits I could muster was my rubber mallet, it's not moving at all. Must be properly stuck on! Car is coming up to 7 y/o and the discs are still the originals.

[Mr2Mike]

Rubber mallets are useless for this kind job, unless it's a proper dead blow hammer. If it's properly seized on then a big lump hammer is likely to be needed.

[dave_s13]

Lump hammer, not rubber mallet.

You often have to get medieval so make sure it's well planted on axel stands and the other wheels chocked and also stick your wheel under the jacking point as a just in case.

[DuraAce]

Rubber mallet? Behave!

Get a BIG metal hammer and hit it. REALLY hit it, rotate and repeat and it'll be off in 20 seconds. Few taps on the front face of the hub to losen any rust up a bit won't do any harm either.

[AllyBassman]

haha! the good ol' rubber mallet worked fine for the fronts, I guess I'll need to get myself a big ol' hammer and try again!

[DuraAce]

Luck of the draw really - sometimes they will almost fall off and others they'll need battering off with a big hammer.

[liner33]

Someone once told me that if you hit them with a metal hammer you can shatter the disc, I remembered that for 20+ years and was always fairly gentle with them , recently had a stuck one and was replacing it so it didnt matter if it broke so I battered the hell out of it with a lump hammer and did it break ? Did it ****

[njw1]

Hit it around the hub and it'll soon come off. Did the rear brakes on my e39 on the weekend and the discs really took some persuading with a big hammer before they came off.

Edited by njw1 on Monday 5th February 17:03

[E-bmw]

Exactly right, hit the hub not the braking surface.

Hit it from the end, hit it from the side all the way round & at some point it will fall offf if the adjuster is backed off & you will know if the adjuster is backed off if you can spin the disc/hub with the handbrake off.

[AllyBassman]

Thanks all,

will get a bigger hammer and try again!

[SebringMan]

How long is a piece of string? Are your bells in the same material as the disc or are they alloy bells?

If they are the same material I'd see if you could see the rear of the bell. If there is rust clear as much of it out as possible. Then whack the disc with a hammer, turning it around as you do and it will eventually get easier. The other option is to put a gear puller type puller onto the disc to remove it that way.

If it's an alloy bell you'll probably need to heat up the area where the bell meets the hub where it will then break free. This can work for the above.

[PaulKemp]

I had the same problem with a Mondeo, didnt have handbrake in the Bell so just corroded on.
As I was replacing the discs I showed it no mercy, i gave it large with a short 2lb club hammer which is a bit heavier with a longer handle than the standard club hammer, I used a butane blow torch a few times then back to the club hammer.

Safety warning, brake fluid will burn well, protect pipes. Wear safety gloves and glasses.

My cousin who is a heavy truck mechanic has a sawn off sledge hammer for tight spaces

[Perseverant]

Sometimes using two hammers opposing will shock things off. Coordination is a bit of a knack but the shock being applied at an outward sort of angle seems to drive discs off.

[PaulKemp]

A few photos of the sawnoff sledge compared with a 2lb ball-peen hammer.
Sledge Head is 10lb and my cousin will Weald that for ½ hour continuously

[AllyBassman]

Well I got it off in the end.. I ended up getting some M10 bolts, nuts and washers, thread one through each caliper carrier bolt hole and tightened them up a little at a time. The sustained pressure of the bolt on the back of the rotor 'popped' it right off.

When Medieval doesn't work, go Victorian!

Edited by AllyBassman on Monday 19th February 11:12

[227bhp]

AllyBassman said:

When Medieval doesn't work, go Victorian!

Made me smile, a good method and good result.