caliper bolts

Hi All, I have a '96 328i. Can anyone tell me what size hex wrench is needed to remove the front brake caliper guide bolts? Also, is it the same size wrench for the rear caliper? TIA to all!

J
Reply to
Jim
Loading thread data ...

"Jim" wrote

They're all the same. IIRC, it's 17mm (although I could be wrong and it's 14mm or so...)

Floyd

Reply to
Floyd Rogers

7mm. Best to get one to fit a 3/8" socket set. But when the discs need replacing you'll need an 8mm (IIRC) for that so get a set.

Yup.

Don't forget to buy a pad wear sensor at the same time as the pads.

Reply to
Dave Plowman (News)

7mm Mike.
Reply to
Mike G

Someone not used to the metric system. ;-)

17mm is *almost* 3/4" (0.67") That would be a *vast* allen head bolt.
Reply to
Dave Plowman (News)

On Thu, 22 Sep 2005 11:14:13 +0100, "Dave Plowman (News)" waffled on about something:

I've got a 46mm 3/4" drive socket somewhere... Maybe he'd like that. Can't remember what I bought it for, must have been a crank pulley or drive shaft nut on something.

Dodgy.

Reply to
Dodgy

If you don't have a 17mm Allen key, use a normal bolt with a 17mm head and lock two 17mm nuts on the other end. I used this to open the oil filler plug on our beetle's gearbox once.

MW

Reply to
MW de Jager

Thought he was asking about the bolt holding the calipers onto the wheel assembly... Biggest socket I have is 36mm for the oil filter cap...

Floyd

Reply to
Floyd Rogers

Ah - I assumed by the 'hex wrench' he meant an allen key - not a spanner. And you need an allen key for the slides on BMW brakes.

I've got larger than that. ;-)

Reply to
Dave Plowman (News)

Thanks to all who posted. Just to clear up the bolt sizes for anyone new to the thread: road wheel= 17mm; rotor to hub=6mm hex; caliper guide bolts=7mm. I removed the caliper and the bolt holding the rotor to the hub but the rotor is stuck fast to the hub. The last brake job was done by the dealer and they have usually done good work for me, so I assume it was installed correctly. I tried to loosen it with a rubber mallet to no avail. I'm hoping to tap into the collective wisdom of the group, once again, for advice! Thanks again to all!

Reply to
Jim

That's most unusual on a BMW.

Since the only reason to remove the disc is if it needs replacing, hit it with large hammer. ;-)

Make sure the mating faces of hub and new disc are spotless, and use a little copper grease to stop it seizing again.

Reply to
Dave Plowman (News)

The disk is trapped on the hub by rust. Try to clean up as much rust along the center hub as you can with a wire brush. You can try using something like PB Blaster on the junction between the rotors and hubs and let that soak in a bit.

Assuming that you are removing the rotors to replace them, hit them harder with a bigger hammer.

Reply to
Malt_Hound

This part is almost pointless except in terms of clearing a path for the penetrant.

Fred is right. You're being much too gentle. You can shoot some penetrating oil of your choice (I tend to use WD-40 or Kroil.) into the bolt holes, too. That distributes it better in there. If you're in the mood and you have a propane torch handy, heat it up a little, but try to stay away from the hub. Heat only the disk hat. I find a sharp oblique blow from a hammer on the hat portion is often enough to break it loose. Remember: you're going to throw this part away, so any damage you do to it is OK.

-- C.R. Krieger (BT, DT)

Reply to
C.R. Krieger

Thanks guys. And I always thought "Use a bigger hammer" was just a joke! I'll try it tomorrow AM and report back. If it wasn't for frozen hubs this would be the easiest brake job I've ever seen. A well designed set-up I think. It's hard to understand why the dealers get $450+ for the job.

Jim

Reply to
Jim

Best way to mark the ball bearings ! Not a cheap part and not easy to replace ;-((

I never ever use a hammer on mechanics except for body work and for very special cases. If you use WD40 or similar, make sure you don't spray on the seals.

"Jim" a écrit dans le message news: snipped-for-privacy@comcast.com...

^^^^^^^^^^^^^^^^^^^^

^^^^^^^^^^^^^^^^^^

Reply to
zantafio

Don't be silly.

Good for you. But how else are you going to remove a stuck disc? And it won't be stuck like some that may need an angle grinder to remove them.

Which seals?

Reply to
Dave Plowman (News)

Many thanks to all who posted. I finally got everything installed this morning, pads, rotors, wear sensor, new rotor to hub bolts. The rotors came off much more easily after cooling completely overnight. A little penetrating oil and a few sharp raps with a rubber mallet did it. I guess I just didn't wait long enough after driving home from work for the rotors to be cool enough to release easily. Just one addendum to the bolt sizes: the pad carrier bolts are 16mm. I saved more than half the cost of what the dealer charged to do the same job last time.

Regards, Jim

Reply to
Jim

I'd be surprised if they let you get near enough. Mike.

Reply to
Mike G

They will, if they think you're going to blow them.

Reply to
Dean Dark

"Dave Plowman (News)" a écrit dans le message news: snipped-for-privacy@davenoise.co.uk...

Not my problem if you ignore the basic rules ! However I wouldn't bring my car for a fix into your garage !

Have a look o this link

formatting link

Callipers, and every seal around, depends on the model and front/rear. Could be between the universal joint to the arm.

Reply to
zantafio

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.